docs(skill): combine CCG search with source lookup

[tae2089]

What changed

• add a hybrid search workflow that pairs direct source lookup with CCG intent and relationship search
• prefer rg for exact repository text, then verify CCG candidates against current source
• require both search modes plus graph-freshness checks before claiming code or behavior is absent
• deduplicate corroborating results while preserving whether they came from exact text, identifiers, recorded reasons, or graph relationships
• narrow the annotation guidance so it triggers only when coverage or next actually says reasons are missing

Why

The skill previously treated grep/read and CCG as separate routing choices. That left agents without an operational rule for cases where indexed intent finds a candidate that direct text misses, direct text finds a candidate ranked off a CCG page, or either source alone appears empty.

Impact

Agents can combine high-recall direct lookup with annotation-aware search without treating either result source as proof it cannot provide. The completion contract now requires source corroboration for absence and completeness claims.

Verification

• CGO_ENABLED=1 go test -tags fts5 ./internal/adapters/inbound/cli ./internal/app/search/wire -count=1
• git diff --check
• isolated SQLite: ccg migrate, ccg build ., ccg docs --out docs, and ccg lint
• generated docs produced no tracked diff; lint reported the existing quality counts only (0 orphan, missing, stale, contradiction, dead-ref, or drifted)

[tae2089]

Self-review completed against the published patch; no actionable P0–P3 findings.

Reviewed contracts:

• the simple exact-file/string lookup exception remains intact
• hybrid lookup is required only when intent, relationships, or completeness can change the answer
• absence claims now require graph freshness plus both indexed and direct-source evidence
• provenance is preserved instead of treating a grep hit as relationship proof or a CCG hit as exact-current-source proof
• the formerly absolute empty-result guidance now delegates to annotation only when coverage or next provides that evidence
• the procedure remains host-neutral and checkable; no production code, test expectation, or generated artifact changed

Local validation passed: skill contract tests, git diff --check, and isolated SQLite migrate/build/docs/lint. CI was still pending at the time of this review.

[tae2089]

CI follow-up: both verify and verify-postgres completed successfully after the review was submitted.