Privacy seams on the OTEL path: inline policy drop, spool deletion, purge and detach sweep

[philcunliffe]

Parent

Implementation spec: #798 (LLP 0245).

What to build

The privacy guarantees hold on the new path with no fail-open window. The .hypignore and machine-local local-only checks run inline at ingest, with cwd known from the retained SessionStart hook, using the existing usage-policy drop sentinel. Ignored or policy-dropped sessions produce zero rows AND their spool bodies are DELETED, never merely skipped. hyp purge and detach both sweep the spool directory.

Acceptance criteria

• OTEL-path analog of the hypignore capture-drop smoke: two sessions, one under .hypignore; only the clean session's rows land, the drop signal fires, and the ignored session's body files are gone from the spool
• No rows written before policy resolution (the fail-open window does not reappear)
• hyp purge sweeps the spool; detach sweeps the spool (using the directory recorded on the marker)
• Machine-local list honored from the shared state root

Blocked by

• Body spool: system text, tools, untruncated args, cap and eviction #804 (spool exists)
• OTEL attach and detach mode for the claude client, with version floor #806 (detach sweep uses the marker)