confide:rehydrate — restore real values into a placeholder analysis

This is the last step of the CONFIDE round-trip:

1. Redact locally with confide:anon (default reversible mode) → a GREEN copy with unique reserved-sentinel placeholders ([CONFIDE_PERSON_0001], [CONFIDE_EMAIL_0001], [CONFIDE_DATE_0002]…) plus a secret <name>.map.json (structured: green_sha256, entries[]…) that stays on the machine.
2. Analyze the GREEN text anywhere — including a cloud LLM. The analysis comes back full of those same placeholders (sometimes mangled to CONFIDE_PERSON_0001, [CONFIDE PERSON 0001]… — but always keeping the full CONFIDE_TYPE_NNNN core).
3. Rehydrate here: replace every placeholder with its original value from your own map, producing the real analysis — without the cloud ever seeing the originals.