feat(review): suppression-signal data model + migration for review memory

[JSONbored]

Data-model slice of #1964: a bounded, public-safe per-repo suppression store (pattern/path/category/created_at) that later slices record into and read from. Migration + typed row + repository accessors only — NO recording trigger and NO apply-during-review logic (those are separate slices). No suppression store exists today (verified).

Deliverables

• New contiguous migration migrations/0088_review_suppression_memory.sql creating a review_suppression table keyed by (project, repo, category, path_glob, pattern_hash) with created_at + bounded columns
• Typed row + insert/list repository functions in src/db/repositories (bounded row cap per repo, fail-safe)
• cf-typegen run + committed if any wrangler binding/var changes (per CLAUDE.md rule 4)
• Tests: insert, list, per-repo bound enforcement, uniqueness/upsert branch (branch-counted)

References

• migrations/0087_github_rate_limit_admission_key.sql
• src/db/repositories.ts
• src/review/review-thread-findings.ts:1

Part of #1964.

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size: S · held for later release (gittensor:feature once activated)

[linear-code]

JSO-2279