Semantic injection always returns empty: project-filter mismatch between Chroma sync and /api/context/semantic

[amellman]

Summary

With CLAUDE_MEM_SEMANTIC_INJECT=true (runtime=worker), the UserPromptSubmit semantic injection returns empty context for every real session. The feature only returns results when queried without a project filter.

Root cause

Two compounding issues:

1. Sync writes the wrong project metadata. Every row in the Chroma collection is tagged project="aaronmellman" — it appears to derive from the worker daemon's cwd (the user's home dir) rather than each observation's originating project. Verified:

   sqlite3 ~/.claude-mem/chroma/chroma.sqlite3 \
     "SELECT string_value, COUNT(*) FROM embedding_metadata WHERE key='project' GROUP BY 1;"
   -> aaronmellman|16392      (single value, all rows)
   

2. Injection queries with a different project value, and the project-filter path returns empty regardless. The hook calls /api/context/semantic with {q, project, limit} where project is the session slug (e.g. business-os-archreview, derived from cwd/git). The endpoint filters where:{project: <param>}. Since the stored value never matches the session slug, results are always empty. Critically, even querying with the stored value (aaronmellman) returns empty, while the unscoped query returns correct matches — so the scoped where-clause path itself looks broken, not just the metadata.

Evidence (curl against the worker, 127.0.0.1:37701)

Request body	count
{"q":"...","limit":5} (no project)	5 (relevant matches)
{"q":"...","project":"aaronmellman","limit":5} (the only stored value)	0
{"q":"...","project":"business-os-archreview","limit":5} (real session slug)	0

Environment

• claude-mem 13.6.1, runtime worker, macOS (Apple Silicon)
• chroma-mcp==0.2.6 persistent, ~16,392 embeddings

Suggested fixes (any one)

1. Tag synced observations with the same project value used at query time (per-observation, not the worker's cwd).
2. Fix the project where-clause so an exact-match value actually filters.
3. Add an env knob (e.g. CLAUDE_MEM_SEMANTIC_INJECT_SCOPE=global) to disable project scoping for injection.

Workaround in use

Dropping the project arg from the inject call in worker-service.cjs ({q:s,project:i,limit:m} -> {q:s,limit:m}) makes injection use the working unscoped path. Reverts on update since it's vendored code.