Retain live processing timings across UI reruns

CHANGELOG.md

@@ -4,6 +4,9 @@
 
 ### Added
 
+- Retained live stage and total timings for processing and protocol regeneration.
+- Immutable diagnostic generation history with atomic latest-result publication.
+
 - Auto/Fast/Efficient/Powersave protocol profiles with backend-selected threads
   by default, also applied during mapped-speaker regeneration.
 

PROJECT_KNOWLEDGE.md

@@ -169,3 +169,14 @@ Active glossary aliases are forwarded to Meeting Lab as provenance metadata.
 Canonical terminology remains Meeting Context guidance; the exact protocol
 transcript input and the raw Whisper/diarization artifacts are not rewritten.
 `glossary_replacements` remains empty.
+
+Processing and protocol regeneration show measured monotonic stage/total timings,
+including frozen failure durations. The latest timing display survives ordinary
+Streamlit reruns. Initial-run durations are saved in `run_metadata.json`;
+regeneration display timings remain session-local. Worker callbacks capture UI
+configuration before dispatch and never read Streamlit session state.
+
+Meeting Lab retains immutable generation records including prompt, transcript
+input, model response/metadata, glossary configuration, mappings and Meeting
+Context. Latest protocol/diagnostic/context paths resolve through an atomic
+`protocol/current` link. Copy whole runs with relative symlinks preserved.

README.md

@@ -234,3 +234,14 @@ Active glossary aliases are forwarded to Meeting Lab as provenance metadata.
 Canonical terminology remains Meeting Context guidance; the exact protocol
 transcript input and the raw Whisper/diarization artifacts are not rewritten.
 `glossary_replacements` remains empty.
+
+Processing and protocol regeneration show measured monotonic stage/total timings,
+including frozen failure durations. The latest timing display survives ordinary
+Streamlit reruns. Initial-run durations are saved in `run_metadata.json`;
+regeneration display timings remain session-local. Worker callbacks capture UI
+configuration before dispatch and never read Streamlit session state.
+
+Meeting Lab retains immutable generation records including prompt, transcript
+input, model response/metadata, glossary configuration, mappings and Meeting
+Context. Latest protocol/diagnostic/context paths resolve through an atomic
+`protocol/current` link. Copy whole runs with relative symlinks preserved.

src/mka/application/meeting_service.py

@@ -21,6 +21,7 @@ from mka.application.glossary import (
     render_glossary_terms,
 )
 from mka.application.performance import DEFAULT_PERFORMANCE_PROFILE, resolve_ollama_num_thread
+from mka.application.progress_timing import ProcessingTimer
 
 STAGES = ("preparing", "transcription", "diarization", "protocol_generation")
 
@@ -120,11 +121,13 @@ class MeetingProcessingService:
         settings: AppSettings,
         meeting_lab: MeetingLabPort,
         glossary: GlossaryRepository | None = None,
+        timer: ProcessingTimer | None = None,
     ) -> None:
         self.settings = settings
         self.meeting_lab = meeting_lab
         self.glossary = glossary or GlossaryRepository(settings.glossary_database)
         self.glossary.initialize()
+        self.timer = timer or ProcessingTimer()
 
     def build_context(
         self,
@@ -235,11 +238,11 @@ class MeetingProcessingService:
                 "model": self.settings.protocol_model,
                 "ollama_endpoint": self.settings.ollama_endpoint,
                 "protocol_num_ctx": self.settings.protocol_num_ctx,
-                "glossary_aliases": glossary_alias_mapping(self.glossary.list(active_only=True)),
-                "protocol_num_thread": resolve_ollama_num_thread(options.performance_profile),
                 "protocol_safe_input_token_budget": (
                     self.settings.protocol_safe_input_token_budget
                 ),
+                "protocol_num_thread": resolve_ollama_num_thread(options.performance_profile),
+                "glossary_aliases": glossary_alias_mapping(self.glossary.list(active_only=True)),
                 "diarization": (
                     self.settings.diarization_mode if options.diarization_enabled else "off"
                 ),
@@ -249,11 +252,13 @@ class MeetingProcessingService:
             }
         )
         current_stage: str | None = None
+        self.timer.start_run()
 
         def relay(event: Any) -> None:
             nonlocal current_stage
             if event.stage in STAGES and event.status == "started":
                 current_stage = event.stage
+            self._update_timer(event)
             app_event = AppProgressEvent(
                 stage=event.stage,
                 status=event.status,
@@ -264,7 +269,13 @@ class MeetingProcessingService:
             if progress_sink is not None:
                 progress_sink(app_event)
 
-        result = self.meeting_lab.run(config, context, relay)
+        try:
+            result = self.meeting_lab.run(config, context, relay)
+        except Exception:
+            self.timer.finish_run()
+            raise
+        self.timer.finish_run()
+        self._persist_timing(result.run_dir)
         if result.exit_code != 0:
             failure = self._read_failure(result.run_dir)
             backend_stage = failure.get("stage")
@@ -392,6 +403,7 @@ class MeetingProcessingService:
         context = self.meeting_lab.create_context(context_data)
 
         def relay(event: Any) -> None:
+            self._update_timer(event)
             if progress_sink is not None:
                 progress_sink(
                     AppProgressEvent(
@@ -403,17 +415,23 @@ class MeetingProcessingService:
                     )
                 )
 
-        result = self.meeting_lab.regenerate_protocol(
-            Path(run_dir),
-            context,
-            relay,
-            model=self.settings.protocol_model,
-            ollama_endpoint=self.settings.ollama_endpoint,
-            protocol_num_ctx=self.settings.protocol_num_ctx,
-            glossary_aliases=glossary_alias_mapping(self.glossary.list(active_only=True)),
-            protocol_num_thread=resolve_ollama_num_thread(performance_profile),
-            protocol_safe_input_token_budget=(self.settings.protocol_safe_input_token_budget),
-        )
+        self.timer.start_run()
+        try:
+            result = self.meeting_lab.regenerate_protocol(
+                Path(run_dir),
+                context,
+                relay,
+                model=self.settings.protocol_model,
+                ollama_endpoint=self.settings.ollama_endpoint,
+                protocol_num_ctx=self.settings.protocol_num_ctx,
+                protocol_safe_input_token_budget=(self.settings.protocol_safe_input_token_budget),
+                protocol_num_thread=resolve_ollama_num_thread(performance_profile),
+                glossary_aliases=glossary_alias_mapping(self.glossary.list(active_only=True)),
+            )
+        except Exception:
+            self.timer.finish_run()
+            raise
+        self.timer.finish_run()
         protocol_path = Path(result.protocol_path)
         return ProcessingOutcome(
             succeeded=True,
@@ -474,3 +492,38 @@ class MeetingProcessingService:
         destination = Path(run_dir) / "protocol_edited.md"
         destination.write_text(text, encoding="utf-8")
         return destination
+
+    def _update_timer(self, event: Any) -> None:
+        """Apply a backend progress event to the shared per-run timer."""
+        if event.stage in STAGES and event.status == "started":
+            self.timer.start_stage(event.stage)
+        elif event.stage in STAGES and event.status in {"completed", "skipped"}:
+            self.timer.finish_stage(event.stage)
+        if event.stage in {"completed", "failed"}:
+            self.timer.finish_run()
+
+    def _persist_timing(self, run_dir: Path | None) -> None:
+        """Merge final monotonic durations into Meeting Lab run metadata."""
+        if run_dir is None:
+            return
+        metadata_path = Path(run_dir) / "run_metadata.json"
+        metadata: dict[str, Any] = {}
+        if metadata_path.is_file():
+            try:
+                existing = json.loads(metadata_path.read_text(encoding="utf-8"))
+                if isinstance(existing, dict):
+                    metadata = existing
+            except (OSError, json.JSONDecodeError):
+                return
+        snapshot = self.timer.snapshot()
+        metadata["timing"] = {
+            "stages_seconds": snapshot.stage_durations,
+            "total_seconds": snapshot.total_duration,
+        }
+        metadata_path.parent.mkdir(parents=True, exist_ok=True)
+        try:
+            metadata_path.write_text(
+                json.dumps(metadata, indent=2, sort_keys=True) + "\n", encoding="utf-8"
+            )
+        except OSError:
+            return

src/mka/application/progress_timing.py

@@ -0,0 +1,80 @@
+"""Thread-safe monotonic timing state for meeting-processing progress."""
+
+from __future__ import annotations
+
+import time
+from collections.abc import Callable
+from dataclasses import dataclass
+from threading import Lock
+
+
+@dataclass(frozen=True)
+class TimingSnapshot:
+    """Presentation-neutral runtime values measured in seconds."""
+
+    stage_durations: dict[str, float]
+    active_stage: str | None
+    total_duration: float
+    running: bool
+
+
+class ProcessingTimer:
+    """Track pipeline stages independently from pipeline business logic."""
+
+    def __init__(self, clock: Callable[[], float] = time.perf_counter) -> None:
+        self._clock = clock
+        self._lock = Lock()
+        self._run_started: float | None = None
+        self._run_finished: float | None = None
+        self._stage_started: dict[str, float] = {}
+        self._stage_finished: dict[str, float] = {}
+        self._active_stage: str | None = None
+
+    def start_run(self) -> None:
+        with self._lock:
+            self._run_started = self._clock()
+            self._run_finished = None
+            self._stage_started.clear()
+            self._stage_finished.clear()
+            self._active_stage = None
+
+    def start_stage(self, stage: str) -> None:
+        with self._lock:
+            now = self._clock()
+            if self._active_stage is not None and self._active_stage != stage:
+                self._stage_finished.setdefault(self._active_stage, now)
+            self._stage_started.setdefault(stage, now)
+            self._active_stage = stage
+
+    def finish_stage(self, stage: str) -> None:
+        with self._lock:
+            if stage in self._stage_started:
+                self._stage_finished.setdefault(stage, self._clock())
+            if self._active_stage == stage:
+                self._active_stage = None
+
+    def finish_run(self) -> None:
+        with self._lock:
+            if self._run_finished is not None:
+                return
+            now = self._clock()
+            if self._active_stage is not None:
+                self._stage_finished.setdefault(self._active_stage, now)
+                self._active_stage = None
+            if self._run_started is not None:
+                self._run_finished = now
+
+    def snapshot(self) -> TimingSnapshot:
+        with self._lock:
+            now = self._run_finished if self._run_finished is not None else self._clock()
+            durations = {
+                stage: max(0.0, self._stage_finished.get(stage, now) - started)
+                for stage, started in self._stage_started.items()
+            }
+            total = max(0.0, now - self._run_started) if self._run_started is not None else 0.0
+            return TimingSnapshot(
+                stage_durations=durations,
+                active_stage=self._active_stage,
+                total_duration=total,
+                running=self._run_started is not None and self._run_finished is None,
+            )

src/mka/ui/streamlit_app.py

@@ -2,7 +2,11 @@
 
 from __future__ import annotations
 
+import time
+from collections.abc import Callable
+from concurrent.futures import ThreadPoolExecutor
 from datetime import date
+from queue import Empty, Queue
 from typing import Any
 from uuid import uuid4
 
@@ -35,6 +39,7 @@ from mka.application.people_yaml import (
     import_people_yaml,
 )
 from mka.application.performance import DEFAULT_PERFORMANCE_PROFILE, PERFORMANCE_PROFILES
+from mka.application.progress_timing import TimingSnapshot
 from mka.application.run_inputs import (
     RunInputJsonError,
     RunInputState,
@@ -338,40 +343,132 @@ def _render_participants() -> list[ParticipantInput]:
     return people
 
 
-def _progress_callback(
+def _format_duration(seconds: float) -> str:
+    """Format numeric seconds as MM:SS or H:MM:SS."""
+    whole_seconds = max(0, int(seconds))
+    hours, remainder = divmod(whole_seconds, 3600)
+    minutes, seconds = divmod(remainder, 60)
+    return f"{hours}:{minutes:02d}:{seconds:02d}" if hours else f"{minutes:02d}:{seconds:02d}"
+
+
+def _render_progress_status(
     status_box: Any,
     stage_table: Any,
-    progress_slot: Any,
     states: dict[str, str],
-) -> Any:
-    progress_bar = None
+    timing: TimingSnapshot,
+    message: str,
+) -> None:
+    suffix = " …" if timing.running else ""
+    status_box.info(f"{message} — total runtime {_format_duration(timing.total_duration)}{suffix}")
+    stage_table.table(
+        [
+            {
+                "Stage": STAGE_LABELS[stage],
+                "Status": states[stage],
+                "Runtime": (
+                    _format_duration(timing.stage_durations[stage])
+                    + (" …" if timing.active_stage == stage else "")
+                    if stage in timing.stage_durations
+                    else ""
+                ),
+            }
+            for stage in STAGES
+        ]
+        + [
+            {
+                "Stage": "Total runtime",
+                "Status": "",
+                "Runtime": _format_duration(timing.total_duration) + suffix,
+            }
+        ]
+    )
 
-    def update(event: AppProgressEvent) -> None:
-        nonlocal progress_bar
-        if event.stage in states:
-            states[event.stage] = "running" if event.status == "started" else event.status
-        if event.stage == "failed":
-            running = next(
+
+def _apply_progress_event(event: AppProgressEvent, states: dict[str, str]) -> None:
+    if event.stage in states:
+        states[event.stage] = "running" if event.status == "started" else event.status
+    if event.stage == "failed":
+        running = next((stage for stage, status in states.items() if status == "running"), None)
+        if running:
+            states[running] = "failed"
+
+
+def _run_with_live_progress(
+    service: MeetingProcessingService,
+    work: Callable[[Callable[[AppProgressEvent], None]], Any],
+    states: dict[str, str],
+    initial_message: str,
+) -> tuple[Any, dict[str, str], str, TimingSnapshot]:
+    """Run pipeline work while rendering the shared timer and progress events."""
+    status_box = st.empty()
+    stage_table = st.empty()
+    progress_slot = st.empty()
+    event_queue: Queue[AppProgressEvent] = Queue()
+    latest_message = initial_message
+    progress_bar = None
+    with ThreadPoolExecutor(max_workers=1) as executor:
+        future = executor.submit(work, event_queue.put)
+        while not future.done():
+            try:
+                while True:
+                    event = event_queue.get_nowait()
+                    _apply_progress_event(event, states)
+                    latest_message = event.message or STAGE_LABELS.get(event.stage, event.stage)
+                    if event.progress is not None:
+                        if progress_bar is None:
+                            progress_bar = progress_slot.progress(0.0)
+                        progress_bar.progress(
+                            min(max(event.progress, 0.0), 1.0),
+                            text=(
+                                f"{STAGE_LABELS.get(event.stage, event.stage)}: "
+                                f"{event.progress:.0%}"
+                            ),
+                        )
+            except Empty:
+                pass
+            _render_progress_status(
+                status_box,
+                stage_table,
+                states,
+                service.timer.snapshot(),
+                latest_message,
+            )
+            time.sleep(0.2)
+        try:
+            result = future.result()
+        except Exception:
+            while not event_queue.empty():
+                event = event_queue.get_nowait()
+                _apply_progress_event(event, states)
+                latest_message = event.message or STAGE_LABELS.get(event.stage, event.stage)
+            service.timer.finish_run()
+            running_stage = next(
                 (stage for stage, status in states.items() if status == "running"),
                 None,
             )
-            if running:
-                states[running] = "failed"
-        elapsed = f"{event.elapsed_seconds:.1f} s"
-        message = event.message or STAGE_LABELS.get(event.stage, event.stage)
-        status_box.info(f"{message} — elapsed {elapsed}")
-        stage_table.table(
-            [{"Stage": STAGE_LABELS[stage], "Status": states[stage]} for stage in STAGES]
-        )
-        if event.progress is not None:
-            if progress_bar is None:
-                progress_bar = progress_slot.progress(0.0)
-            progress_bar.progress(
-                min(max(event.progress, 0.0), 1.0),
-                text=f"{STAGE_LABELS.get(event.stage, event.stage)}: {event.progress:.0%}",
-            )
+            if running_stage is not None:
+                states[running_stage] = "failed"
+            snapshot = service.timer.snapshot()
+            _render_progress_status(status_box, stage_table, states, snapshot, latest_message)
+            st.session_state["processing_progress"] = (states.copy(), latest_message, snapshot)
+            raise
+    while not event_queue.empty():
+        event = event_queue.get_nowait()
+        _apply_progress_event(event, states)
+        latest_message = event.message or STAGE_LABELS.get(event.stage, event.stage)
+    running_stage = next((stage for stage, status in states.items() if status == "running"), None)
+    if running_stage is not None:
+        states[running_stage] = "completed" if getattr(result, "succeeded", True) else "failed"
+    snapshot = service.timer.snapshot()
+    _render_progress_status(status_box, stage_table, states, snapshot, latest_message)
+    st.session_state["processing_progress"] = (states.copy(), latest_message, snapshot)
+    return result, states, latest_message, snapshot
 
-    return update
+
+def _remember_regeneration_timing(
+    states: dict[str, str], message: str, timing: TimingSnapshot
+) -> None:
+    st.session_state["regeneration_progress"] = (states.copy(), message, timing)
 
 
 def _speaker_options(
@@ -447,6 +544,9 @@ def _render_result() -> None:
         return
     st.divider()
     st.header("Protocol result")
+    if retained_progress := st.session_state.get("processing_progress"):
+        states, message, timing = retained_progress
+        _render_progress_status(st.empty(), st.empty(), states, timing, message)
     if not outcome.succeeded:
         st.error(f"Processing failed during {outcome.failed_stage}: {outcome.error_message}")
         if outcome.run_dir:
@@ -494,18 +594,33 @@ def _render_result() -> None:
         disabled=duplicate_assignments,
         type="primary",
     ):
+        st.session_state.pop("regeneration_progress", None)
+        run_dir = outcome.run_dir
+        mapping_items = tuple(selections.items())
+        selected_profile = st.session_state.get("performance_profile", DEFAULT_PERFORMANCE_PROFILE)
+        states = {stage: "skipped" for stage in STAGES}
+        states["protocol_generation"] = "pending"
         try:
-            with st.spinner("Regenerating protocol without rerunning audio processing..."):
-                regenerated = service.regenerate_protocol(
-                    outcome.run_dir,
-                    selections,
-                    performance_profile=st.session_state.get(
-                        "performance_profile", DEFAULT_PERFORMANCE_PROFILE
-                    ),
-                )
+            regenerated, states, message, timing = _run_with_live_progress(
+                service,
+                lambda progress_sink: service.regenerate_protocol(
+                    run_dir,
+                    dict(mapping_items),
+                    progress_sink=progress_sink,
+                    performance_profile=selected_profile,
+                ),
+                states,
+                "Starting protocol regeneration",
+            )
         except (OSError, RuntimeError, ValueError) as exc:
+            _remember_regeneration_timing(
+                states,
+                "Protocol regeneration failed",
+                service.timer.snapshot(),
+            )
             st.error(f"Protocol regeneration failed: {exc}")
         else:
+            _remember_regeneration_timing(states, message, timing)
             st.session_state.outcome = regenerated
             _queue_edited_protocol(regenerated.original_protocol or "")
             st.session_state.speaker_mapping_message = (
@@ -618,31 +733,34 @@ def main() -> None:
                 )
                 meeting_id = stable_id(title)
                 audio_path = service.preserve_upload(meeting_id, audio.name, audio)
+                st.session_state.pop("regeneration_progress", None)
+                st.session_state.pop("processing_progress", None)
                 st.header("Processing status")
-                status_box = st.empty()
-                stage_table = st.empty()
-                progress_slot = st.empty()
                 states = {stage: "pending" for stage in STAGES}
                 if not diarization_enabled:
                     states["diarization"] = "skipped"
-                callback = _progress_callback(status_box, stage_table, progress_slot, states)
-                outcome = service.process(
-                    audio_path,
-                    meeting,
-                    participants,
-                    ProcessingOptions(
-                        diarization_enabled=diarization_enabled,
-                        audio_normalization=audio_normalization,
-                        performance_profile=performance_profile,
+                outcome, _, _, _ = _run_with_live_progress(
+                    service,
+                    lambda progress_sink: service.process(
+                        audio_path,
+                        meeting,
+                        participants,
+                        ProcessingOptions(
+                            diarization_enabled=diarization_enabled,
+                            audio_normalization=audio_normalization,
+                            performance_profile=performance_profile,
+                        ),
+                        progress_sink=progress_sink,
                     ),
-                    progress_sink=callback,
+                    states,
+                    "Starting processing",
                 )
                 st.session_state.outcome = outcome
                 st.session_state.edited_protocol = outcome.original_protocol or ""
                 if outcome.succeeded:
-                    status_box.success("Processing completed.")
+                    st.success("Processing completed.")
                 else:
-                    status_box.error(
+                    st.error(
                         f"Processing failed during {outcome.failed_stage}: "
                         f"{outcome.error_message} Artifacts were preserved."
                     )

tests/test_live_progress_ui.py

@@ -0,0 +1,88 @@
+"""Exercise the real executor and Streamlit reruns without model calls."""
+
+from pathlib import Path
+from threading import current_thread
+from types import SimpleNamespace
+
+import pytest
+import streamlit
+from streamlit.testing.v1 import AppTest
+
+from mka.application.meeting_service import AppProgressEvent, SpeakerMappingReview, SpeakerReview
+from mka.application.progress_timing import ProcessingTimer
+from mka.ui import streamlit_app as ui
+
+
+class GuardedStreamlit:
+    """Fail if a worker touches the UI session proxy, including callback reads."""
+
+    def __getattr__(self, name):
+        if name == "session_state" and current_thread().name.startswith("ThreadPoolExecutor"):
+            raise AssertionError("Worker accessed Streamlit session state")
+        return getattr(streamlit, name)
+
+
+@pytest.mark.parametrize("fails", [False, True])
+@pytest.mark.parametrize("mapped", [False, True])
+def test_regeneration_captures_ui_values_before_real_worker_and_retains_timing(
+    monkeypatch, fails, mapped
+):
+    outcome = SimpleNamespace(
+        succeeded=True,
+        run_dir=Path("/tmp/alpha-mapping-test"),
+        speaker_attribution_available=True,
+        original_protocol="Existing protocol",
+    )
+    review = SpeakerMappingReview((SpeakerReview("SPEAKER_00", ()),), (("a", "A"),), {})
+    calls = []
+
+    class Service:
+        def __init__(self, *args):
+            self.timer = ProcessingTimer()
+
+        def load_speaker_mapping_review(self, run_dir):
+            return review
+
+        def regenerate_protocol(self, run_dir, selections, *, progress_sink, performance_profile):
+            assert current_thread().name.startswith("ThreadPoolExecutor")
+            calls.append((run_dir, selections, performance_profile))
+            self.timer.start_run()
+            self.timer.start_stage("protocol_generation")
+            progress_sink(AppProgressEvent("protocol_generation", "started", 0.0))
+            if fails:
+                raise RuntimeError("model unavailable")
+            self.timer.finish_stage("protocol_generation")
+            self.timer.finish_run()
+            progress_sink(AppProgressEvent("protocol_generation", "completed", 0.0))
+            return outcome
+
+    monkeypatch.setattr(ui, "st", GuardedStreamlit())
+    monkeypatch.setattr(ui, "MeetingProcessingService", Service)
+    monkeypatch.setattr(ui.AppSettings, "from_environment", lambda: None)
+    monkeypatch.setattr(ui, "MeetingLabGateway", lambda: None)
+
+    def result_app(outcome):
+        import streamlit as st
+
+        from mka.ui.streamlit_app import _render_result
+
+        st.session_state.outcome = outcome
+        st.session_state.performance_profile = "fast"
+        _render_result()
+
+    app = AppTest.from_function(result_app, args=(outcome,)).run()
+    if mapped:
+        app.selectbox[0].select("a").run()
+    button = next(button for button in app.button if "Regenerate" in button.label)
+    assert not button.disabled
+    button.click().run()
+    assert not app.exception
+    assert calls == [(outcome.run_dir, {"SPEAKER_00": "a"} if mapped else {}, "fast")]
+    states, message, timing = app.session_state["processing_progress"]
+    assert states["protocol_generation"] == ("failed" if fails else "completed")
+    assert not timing.running
+    assert timing.total_duration >= timing.stage_durations["protocol_generation"] >= 0
+    app.run()
+    assert not app.exception
+    assert app.session_state["processing_progress"][2] == timing
+    assert any("total runtime" in item.value for item in app.info)

tests/test_meeting_service.py

@@ -14,6 +14,7 @@ from mka.application.meeting_service import (
     ParticipantInput,
     ProcessingOptions,
 )
+from mka.application.progress_timing import ProcessingTimer
 
 
 @dataclass
@@ -623,3 +624,111 @@ def test_process_passes_only_active_explicit_glossary_aliases(tmp_path: Path) ->
 
     assert gateway.config_values is not None
     assert gateway.config_values["glossary_aliases"] == {"Lumini": "Luminy"}
+
+
+@pytest.mark.parametrize("fails", [False, True])
+def test_process_persists_completed_and_failed_timings(tmp_path: Path, fails: bool) -> None:
+    service, gateway = make_service(tmp_path)
+    gateway.fail = fails
+    values = iter([0.0, 1.0, 9.0, 10.0, 20.0])
+    service.timer = ProcessingTimer(lambda: next(values))
+    audio = tmp_path / "meeting.wav"
+    audio.write_bytes(b"audio")
+
+    outcome = service.process(audio, meeting(), participants(), ProcessingOptions())
+
+    metadata = json.loads((gateway.run_dir / "run_metadata.json").read_text(encoding="utf-8"))
+    assert metadata["timing"] == {
+        "stages_seconds": {"preparing": 8.0, "transcription": 10.0},
+        "total_seconds": 20.0,
+    }
+    assert outcome.succeeded is not fails
+    if fails:
+        assert metadata["failure"]["type"] == "TranscriptionError"
+
+
+def test_regeneration_starts_fresh_timer_and_retains_final_duration(
+    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    service, gateway = make_service(tmp_path)
+    write_speaker_review_artifacts(gateway.run_dir)
+    clock = SimpleNamespace(value=10.0)
+    service.timer = ProcessingTimer(lambda: clock.value)
+    audio = tmp_path / "meeting.wav"
+    audio.write_bytes(b"audio")
+    service.process(audio, meeting(), participants(), ProcessingOptions())
+
+    clock.value = 100.0
+    observed = []
+
+    def regenerate(run_dir: Path, context: Any, progress_sink: Any, **options: Any) -> Any:
+        progress_sink(
+            SimpleNamespace(
+                stage="protocol_generation",
+                status="started",
+                elapsed_seconds=0.0,
+                progress=None,
+                message=None,
+            )
+        )
+        clock.value = 105.0
+        observed.append(service.timer.snapshot())
+        progress_sink(
+            SimpleNamespace(
+                stage="protocol_generation",
+                status="completed",
+                elapsed_seconds=5.0,
+                progress=None,
+                message=None,
+            )
+        )
+        clock.value = 109.0
+        protocol = run_dir / "protocol.md"
+        protocol.write_text("# Regenerated protocol\n", encoding="utf-8")
+        return SimpleNamespace(run_dir=run_dir, protocol_path=protocol)
+
+    monkeypatch.setattr(gateway, "regenerate_protocol", regenerate)
+
+    service.regenerate_protocol(gateway.run_dir, {"SPEAKER_00": "martin"})
+    final = service.timer.snapshot()
+
+    assert observed[0].active_stage == "protocol_generation"
+    assert observed[0].stage_durations == {"protocol_generation": 5.0}
+    assert observed[0].total_duration == 5.0
+    assert observed[0].running is True
+    assert final.stage_durations == {"protocol_generation": 5.0}
+    assert final.total_duration == 9.0
+    assert final.running is False
+
+
+def test_failed_regeneration_freezes_active_and_total_durations(
+    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    service, gateway = make_service(tmp_path)
+    write_speaker_review_artifacts(gateway.run_dir)
+    clock = SimpleNamespace(value=20.0)
+    service.timer = ProcessingTimer(lambda: clock.value)
+
+    def fail_regeneration(run_dir: Path, context: Any, progress_sink: Any, **options: Any) -> Any:
+        progress_sink(
+            SimpleNamespace(
+                stage="protocol_generation",
+                status="started",
+                elapsed_seconds=0.0,
+                progress=None,
+                message=None,
+            )
+        )
+        clock.value = 27.0
+        raise RuntimeError("generation failed")
+
+    monkeypatch.setattr(gateway, "regenerate_protocol", fail_regeneration)
+
+    with pytest.raises(RuntimeError, match="generation failed"):
+        service.regenerate_protocol(gateway.run_dir, {})
+    clock.value = 99.0
+    final = service.timer.snapshot()
+
+    assert final.stage_durations == {"protocol_generation": 7.0}
+    assert final.total_duration == 7.0
+    assert final.running is False

tests/test_progress_timing.py

@@ -0,0 +1,45 @@
+from mka.application.progress_timing import ProcessingTimer
+
+
+class FakeClock:
+    def __init__(self, value: float = 0.0) -> None:
+        self.value = value
+
+    def __call__(self) -> float:
+        return self.value
+
+
+def test_completed_duration_is_retained_while_active_stage_increases() -> None:
+    clock = FakeClock(10.0)
+    timer = ProcessingTimer(clock)
+    timer.start_run()
+    timer.start_stage("preparing")
+    clock.value = 18.0
+    timer.finish_stage("preparing")
+    timer.start_stage("transcription")
+
+    clock.value = 20.0
+    first = timer.snapshot()
+    clock.value = 25.5
+    second = timer.snapshot()
+
+    assert first.stage_durations == {"preparing": 8.0, "transcription": 2.0}
+    assert second.stage_durations == {"preparing": 8.0, "transcription": 7.5}
+    assert second.total_duration == 15.5
+
+
+def test_failed_active_stage_and_total_duration_are_frozen() -> None:
+    clock = FakeClock(2.0)
+    timer = ProcessingTimer(clock)
+    timer.start_run()
+    clock.value = 5.0
+    timer.start_stage("transcription")
+    clock.value = 14.0
+    timer.finish_run()
+    clock.value = 99.0
+
+    snapshot = timer.snapshot()
+
+    assert snapshot.stage_durations["transcription"] == 9.0
+    assert snapshot.total_duration == 12.0
+    assert snapshot.running is False

tests/test_streamlit_app.py

@@ -1,6 +1,7 @@
 from datetime import date
 
 from mka.application.meeting_service import ParticipantInput
+from mka.application.progress_timing import TimingSnapshot
 from mka.application.run_inputs import RunInputState
 from mka.ui import streamlit_app
 
@@ -66,3 +67,29 @@ def test_imported_inputs_are_applied_via_pending_state_before_widgets(
     assert "source_media_1" not in state
     assert "pending_run_inputs" not in state
     assert state["source_media_0"] is existing_upload
+
+
+def test_duration_formatting_covers_seconds_minutes_and_hours() -> None:
+    assert streamlit_app._format_duration(8.9) == "00:08"
+    assert streamlit_app._format_duration(7 * 60 + 18) == "07:18"
+    assert streamlit_app._format_duration(3600 + 3 * 60 + 42) == "1:03:42"
+
+
+def test_completed_regeneration_timing_survives_frontend_rerun(monkeypatch) -> None:
+    state = {}
+    monkeypatch.setattr(streamlit_app.st, "session_state", state)
+    timing = TimingSnapshot(
+        stage_durations={"protocol_generation": 4.5},
+        active_stage=None,
+        total_duration=4.5,
+        running=False,
+    )
+    states = {stage: "skipped" for stage in streamlit_app.STAGES}
+    states["protocol_generation"] = "completed"
+
+    streamlit_app._remember_regeneration_timing(states, "Protocol regenerated", timing)
+
+    saved_states, saved_message, saved_timing = state["regeneration_progress"]
+    assert saved_states["protocol_generation"] == "completed"
+    assert saved_message == "Protocol regenerated"
+    assert saved_timing == timing