Eliminates the manual cascade-trace ritual when debugging "why can't
alice see /Project-X" reports. New endpoint returns the resolved
policy chain plus the active decider's verdict in JSON:
GET /.profile/effective-policy?path=/Project-X/sub/&email=alice@…
Response shape:
{
"path": "/Project-X/sub/",
"email": "alice@…",
"decision": true,
"decider_kind": "*policy.InternalDecider",
"chain": {
"has_any_file": true,
"levels": [
{"index": 0, "zddc_path": "/.zddc", "exists": true,
"acl": {...}, "admins": [...],
"matches_email": false, "decision_at_level": "no_match"},
{"index": 1, "zddc_path": "/Project-X/.zddc", "exists": true,
"acl": {...}, "matches_email": true, "decision_at_level": "allow"}
]
}
}
Per-level email matching reuses the same MatchesPattern code the live
evaluator uses, so the trace can never disagree with the actual
verdict — and when ZDDC_OPA_URL points at an external OPA, the
decision goes through that OPA, making the endpoint a useful smoke
test for OPA wiring too.
Admin-only via the existing /.profile gate (404 to non-admins).
Required params; 400 if either is missing or path doesn't escape ROOT.
Test coverage:
* TestServeProfileGateMatrix: anonymous → 404, non-admin → 404,
admin without params → 400 (gate cleared, validator rejected)
* TestServeProfileEffectivePolicy: full payload-shape assertion
against a worked-example fixture (closed project where alice is
allow-listed but bob is not)
Also fixes pre-existing doc drift: README's "Admin Debug Page"
section referenced /.admin/whoami|config|logs but the actual code
mounts /.profile/* (the rename predates this PR; the doc was stale).
Closes the "/.admin/effective-policy debug endpoint" item from the
federal-readiness future-work list.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>