feat(server): add institutional memory recall

- File-based memory under .boocode/memory/ (project/user/reference topics)
- Hierarchical 4-scope scan: global → home → project → session
- Keyword/tag relevance matching for query-based recall
- Injected as <boocode-memory> block in system prompt at assembly
- v1 recall-only (extract/dream deferred to v2)

apps/server/src/services/memory/index.ts

@@ -0,0 +1,6 @@
+export { loadMemoryForSession } from './recall.js';
+export { formatMemoryBlock } from './prompt.js';
+export { scanMemoryScopes } from './scan.js';
+export { parseMemoryEntries } from './entries.js';
+export { ensureMemoryScaffold, getMemoryRoot } from './paths.js';
+export type { MemoryEntry } from './entries.js';