Document canonicalization and consolidation milestone

- preserve Working Protocol Synthesizer V0 as comparison baseline
- introduce deterministic canonicalization stage
- define semantic consolidator responsibilities
- clarify Canonical Meeting Knowledge generation
- document source-language output policy
- align roadmap, architecture and experiment log

docs/architecture.md

@@ -98,7 +98,9 @@ Topic Segmentation
     ↓
 Specialized Extraction
     ↓
-Consolidation
+Deterministic Canonicalization
+    ↓
+Semantic Consolidation
     ↓
 Canonical Meeting Knowledge
     ↓
@@ -174,14 +176,32 @@ Each extractor has exactly one task and one prompt.
 
 ## consolidation/
 
-Merges information extracted from multiple discussion segments.
+Planned area for canonicalization and consolidation.
 
-Typical responsibilities:
+The next milestone splits this into two stages.
 
-- merge duplicates
-- combine partial information
-- distinguish positions from decisions
-- detect contradictions
+Deterministic Canonicalizer:
+
+- implemented in Python
+- uses no LLM
+- validates and normalizes extraction objects
+- assigns stable source references and IDs
+- normalizes category names and basic field structure
+- performs only safe deterministic cleanup
+- may group exact duplicates
+- preserves all source evidence
+- must not perform uncertain semantic merging
+
+Semantic Consolidator:
+
+- uses the local LLM
+- merges semantically equivalent statements
+- groups content by topic
+- preserves evidence from all contributing chunks
+- marks contradictions and uncertainty
+- separates durable information from transient discussion
+- produces Canonical Meeting Knowledge
+- does not directly write a protocol
 
 ---
 
@@ -207,6 +227,10 @@ The planned output products are:
 These are parallel renderings of the same canonical semantic model, not
 documents derived from one another.
 
+Rendered protocol language should normally match the dominant language of the
+source transcript or consolidated meeting knowledge unless an explicit output
+language is requested.
+
 ---
 
 # Repository Layout
@@ -257,20 +281,10 @@ Views documented in `output-views.md`.
 
 # Next Milestone
 
-The next development step is the implementation of **topic segmentation**.
-
-Its only responsibility is to identify the thematic structure of a discussion.
-
-It should answer questions such as:
-
-- Where does a topic begin?
-- Where does it end?
-- When does another topic start?
-- When is an earlier topic resumed?
-
-No facts, decisions or todos should be extracted at this stage.
-
-Only after reliable topic segmentation has been achieved will the specialized extraction modules be implemented.
+The next architecture milestone is the implementation of a deterministic
+canonicalization stage followed by a semantic consolidation stage. These stages
+convert raw chunk extraction JSON into evidence-preserving Canonical Meeting
+Knowledge before any Output View renderer writes a protocol.
 
 ---