feat: implement scope cache memory governance (BL-045)

[tryweb]

Summary

• BL-045 implementation complete: Scope cache memory governance with LRU eviction
• All tests passing
• Documentation updated

Verification

• openspec verify-change: passed
• Unit tests: 5/5 passed
• Effectiveness tests: 31/31 foundation + 32/32 regression passed

Changes

• Added ScopeCacheConfig, ScopeCacheEntry, CacheStats interfaces
• Implemented LRU eviction in getCachedScopes()
• Added bounds enforcement (maxScopes, maxRecordsPerScope)
• Added unit tests for cache behavior

Changelog

internal-only (not user-facing)

Changes

.opencode/skills/backlog-complete-merge/SKILL.md | 426 +++++++++++++++++++++
Dockerfile.opencode | 1 +
docs/backlog.md | 2 +-
docs/roadmap.md | 4 +-
.../.openspec.yaml | 2 +
.../design.md | 45 +++
.../proposal.md | 26 ++
.../specs/bounded-scope-cache/spec.md | 83 ++++
.../tasks.md | 28 ++
src/store.ts | 82 +++-
test/unit/scope-cache.test.ts | 109 ++++++
11 files changed, 797 insertions(+), 11 deletions(-)