Denormalize state.isArchived into SQLite metadata to eliminate per-state JSONL reads in getStates

[ProfSynapse]

Motivation

MemoryService.getStates (post-B1 read-path fix in #218 / v5.9.7) calls adapter.getState for every state in the workspace to surface state.metadata.isArchived. This is O(N) JSONL reads per UI/LLM listStates call.

• Fine for small workspaces (<50 states).
• Will degrade for power-user workspaces hitting 100–500+ states.

The "tagged-state shortcut" that previously caused archive-visibility bugs (#218) existed precisely because the original author tried to skip these reads — but the shortcut traded correctness for perf. Denormalizing isArchived into SQLite metadata restores the perf win without sacrificing correctness.

Scope sketch (~80–120 LoC)

1. v12→v13 schema migration: add is_archived INTEGER DEFAULT 0 column to the states metadata table.
2. WorkspaceEventApplier.applyStateSaved: write isArchived from content.state.metadata.isArchived (default 0/false).
3. WorkspaceEventApplier.applyStateUpdated: handle isArchived field updates (parse from data.stateJson when present).
4. IStorageAdapter.getStates: expose isArchived in StateMetadata result rows.
5. MemoryService.getStates: restore the conditional await adapter.getState — now safe to skip when metadata is complete. New shortcut shape:

   const fullState = (stateMeta.tags && stateMeta.isArchived !== undefined)
     ? null
     : await adapter.getState(stateMeta.id);

   Or simpler: pass isArchived through stateMetadataToWorkspaceState directly when fullState is null.
6. Regression tests: MemoryServiceGetStates.test.ts (from fix(memoryManager): surface isArchived from getStates for tagged states #218) should be updated to verify the SQLite path returns isArchived without calling adapter.getState.

References

• PR fix(memoryManager): surface isArchived from getStates for tagged states #218 — read-path fix (current implementation; this issue tracks restoring the perf shortcut).
• PR feat: state CRUA tools + states management UI (#215) #216 — original state CRUA tools + UI section (issue memoryManager: archiveState / deleteState not exposed in CLI (only createState/listStates/loadState) #215).