feat: lat.md integration, knowledge cross-references, and integrity checking

[BYK]

Summary

• lat.md/ reader: Automatically indexes sections from lat.md knowledge graph files. Sections are FTS5-indexed and included in recall results via RRF fusion. Relevant sections are injected into the system prompt alongside LTM entries. Content-hash-based change detection skips unchanged files on re-scan.

• Knowledge cross-references: Entries can link to each other with [[uuid]] (curator — O(1) lookup) or [[Title Text]] (human AGENTS.md edits — FTS5 search). Tracked in knowledge_refs join table. Dead refs are auto-cleaned when entries are deleted or consolidated.

• Integrity checking: ltm.check() detects duplicate entries (by FTS5 title similarity), oversized content (>1200 chars), and empty entries. Runs after curation/consolidation on idle.

Changes

File	What
src/lat-reader.ts	NEW — lat.md parser, section extraction, FTS indexing, scored search
src/db.ts	Migration 10: lat_sections + FTS5 + knowledge_refs tables
src/reflect.ts	lat-section source in RRF fusion
src/ltm.ts	resolveRef, extractRefs, syncRefs, cascadeRefReplace, cleanDeadRefs, check(), lat.md sections in forSession()
src/index.ts	Startup + idle lat-reader refresh, dead-ref cleanup
src/curator.ts	syncRefs after create/update
src/prompt.ts	Cross-reference guidance in curator prompt
src/search.ts	Export filterTerms()
README.md	lat.md compatibility section, cross-references
package.json	Version bump 0.7.1 → 0.8.0
test/lat-reader.test.ts	10 tests
test/refs.test.ts	11 tests
test/integrity.test.ts	4 tests

329 tests pass, 0 failures.