feat(repo)!: retire the summarizer package and LLM symbol-summary feature

[theagenticguy]

What

Retires the LLM code-summarization capability end to end. A capable coding agent regenerates task-conditioned summaries better than an index-time generic summary, so OpenCodeHub now hands agents deterministic structure (locations, edges, blast-radius, owners, license facts) and leaves prose to the agent. Removing summaries also drops the one non-deterministic ingestion phase, so every OpenCodeHub output is now re-derivable.

Removed (BREAKING)

• @opencodehub/summarizer package — deleted entirely.
• Ingestion summarize phase — removed from the default phase set.
• Storage — the symbol_summaries table + DDL, SymbolSummaryRow, and the four SymbolSummary* ITemporalStore methods (bulkLoad / lookup / lookupByNode / count).
• Retrieval — MCP query and CLI query summary-fusion (the join, the summary / signatureSummary fields, the summaries_joined probe).
• CLI flags — codehub analyze --summaries / --no-summaries / --max-summaries / --summary-model (and the CODEHUB_BEDROCK_SUMMARIES / CODEHUB_BEDROCK_DISABLED env vars); codehub wiki --llm / --max-llm-calls / --llm-model. codehub wiki is now deterministic-only.
• Deps — the now-orphaned @aws-sdk/client-bedrock-runtime from @opencodehub/ingestion and @opencodehub/wiki.
• Docs/config — the dedicated summarization-and-fusion.md architecture page, ~15 adjacent doc references, the tsconfig project refs, and the summarizer commitlint scope.

Determinism is unaffected

Summaries never entered graphHash / packHash (see storage/interface.ts — "Summaries never participate in [the hash]"), so the determinism + cross-adapter parity contract is unchanged. The parity suite stays green.

Notable

The embeddings phase gains a direct dep on confidence-demote to preserve its canonical last-in-pipeline ordering (it must observe the final reconciled graph). That ordering previously arrived transitively via the now-removed summarize phase; pinning it directly is behavior-preserving and covered by the phase-order regression test.

Verification

• Full test suite green: 0 failures across all 20 packages, including the graphHash parity suite.
• biome check, typecheck (CI filter, docs excluded per ci.yml), and banned-strings all pass.
• Pre-push gate (typecheck + test + verdict) passed on push.

Diff: 72 files, +145 / −8266.