Add incremental adapter compiler boundary

docs/USER_MANUAL.md

@@ -16,7 +16,10 @@ declared rendering, and the Nodes/Flow/Web visualization model documented below.
 - Disposable SQLite indexing with lexical search, filters, backlinks, dependencies, and impact.
 - Bounded context profiles for AI agents, including source paths and content hashes.
 - Isolated, optimistic changesets with create, update, move, delete, validation, diffs, and previews.
+- Relationship-only changeset operations that do not rewrite node content.
 - Hash-bound canonical application through both CLI and an explicitly enabled MCP tool.
+- Opt-in incremental adapter extraction with reverse-dependency invalidation.
+- Lazy function-scoped logic projections that do not densify the primary graph.
 - Declared HTML render views. Arbitrary templates, render commands, and output paths are rejected.
 - A loopback-only graph browser with Nodes, semantic Flow, and convergence Web views,
   relationship keys, source inspection, branch-aware node hiding, panel resizing, zooming, and
@@ -463,6 +466,7 @@ Example MCP client configuration:
 - `docforge_propose_node_create`
 - `docforge_propose_node_update`
 - `docforge_propose_node_move`
+- `docforge_propose_relationship_update`
 - `docforge_propose_node_delete`
 - `docforge_validate_changeset`
 - `docforge_get_changeset_diff`
@@ -487,9 +491,34 @@ Recommended agent sequence:
 7. Call `docforge_apply_changeset` with that exact hash.
 8. Report changed canonical files and derived refresh results.
 
+Use `docforge_propose_relationship_update` when the intended change is only an edge addition or
+removal. It uses the same underlying validated update contract, but rejects empty relationship
+lists and makes it explicit that node content will remain unchanged.
+
 Custom adapters may expose the application tool only when they supply a project-owned
 `CanonicalApplier`. Core DocForge will not guess how adapter nodes map back to canonical sources.
 
+## Incremental adapter compilation
+
+Release 1 complete-projection adapters remain supported. Adapters with large source trees can
+implement the optional source-scoped manifest and extraction contract. DocForge then fingerprints
+sources, reuses unchanged facts, reparses changed sources and their reverse dependents, validates a
+complete candidate graph, and publishes the index atomically.
+
+Build results report cache hits, reparsed sources, invalidated sources, deleted sources, and total
+sources. A full projection remains the fallback and equivalence oracle.
+
+Manual proposals remain separate from compilation. Applying an approved changeset updates
+canonical sources first. Incremental compilation then notices those changed source fingerprints;
+it never treats an unapplied proposal as canonical.
+
+Function-scoped `LogicProjection` data is cached alongside its owning source but remains separate
+from the primary Nodes, Flow, and Web graph. This is the storage boundary for a future boolean and
+control-flow view without adding every condition and basic block to ordinary graph traversal.
+
+See [Incremental Adapter Indexing](INCREMENTAL_INDEXING.md) for the complete contract, cache
+invalidation rules, manual-application lifecycle, and lazy Logic boundary.
+
 ## Troubleshooting
 
 ### `stale_index` or `visualization_stale`