Kind 30175 persona sync events carry plaintext `system_prompt` and
`respond_to_allowlist`. This PR adds **author-only-unless-shared read
semantics**: events without `["shared","true"]` are visible only to the
author; events with that tag are community-readable.
## What changed
### New read class (kind 30175)
Kind 30175 gets per-event gating at every relay read surface. The
`shared` marker is a **tag**, not a content field, so content bytes
(which double as the `source_version` drift basis) are not affected when
toggling share state.
### `event_visible_to_reader` helper (`handlers/req.rs`)
Centralizes the three per-event access predicates —
`is_author_only_event`, `is_unshared_persona_event`,
`reader_authorized_for_event` — into one `pub(crate)` fn callable from
both WS and HTTP adapters. All result-visibility sites now call this
single helper.
### NIP-98 HTTP bridge (`api/bridge.rs`)
- `POST /query` catchall: replaced the two-step author-only +
result-gated checks with `event_visible_to_reader` (now also covers the
persona shared-gate).
- `POST /count`: added `needs_persona_filtering` to the fast-path guard
(forces per-event fallback when filter can match `kind:30175`) and
replaced both fallback loops' individual checks with
`event_visible_to_reader`.
- FTS `/search` bridge helper: replaced `is_author_only_event` with
`event_visible_to_reader` as defense-in-depth (30175 is not in the FTS
allowlist today; comment at site explains the future-proofing intent).
### Ingest validation (`handlers/ingest.rs`)
`validate_persona_envelope` rejects malformed `shared` tags: wrong
value, missing value, duplicates. Accepts exactly `["shared","true"]`
and tag-absent.
### Kind helpers (`buzz-core/src/kind.rs`)
`is_persona_shared_kind`, `is_unshared_persona_event`,
`filter_can_match_persona_shared_kinds`.
### Tests (`e2e_persona.rs`)
8 unit tests in `kind.rs`, 6 in `ingest.rs`, 8 e2e tests total:
- AC-1–6 covering the gated surfaces
- `test_persona_live_fanout_shared_gate`: reworked with explicit
monotonic `created_at` timestamps (t0 < t1 < t2) and per-step head
assertions, eliminating the NIP-33 event-id tie-break race. Also asserts
foreign live subscription receives nothing on shared→unshared
transition.
- `test_persona_ingest_shared_tag_validation`: added `shared=x` and
missing-value wire-level rejection cases.
- `test_persona_mixed_kind_filter_does_not_leak`: publishes a kind-9
event and asserts it IS returned; absence-only assertion no longer
sufficient.
- `test_persona_http_query_cross_author_gate`: NIP-98 `/query`
cross-author gate (authors filter, kindless `ids` — both blocked; shared
`ids` — passes).
- `test_persona_http_count_cross_author_gate`: NIP-98 `/count`
cross-author gate (foreign sees 1/shared, author sees all, wildcard
checked).
### NIP-AP.md
Replaced aspirational "every relay read chokepoint" wording with an
enumerated list of gated surfaces including NIP-98 `/query`, `/count`,
and FTS/search with their enforcement mechanism named. Added
**Non-goal** note for side-band existence oracles
(reaction/report/deletion target resolution).
## Existing tests
All pre-existing `e2e_persona` tests use `{ids:[event_id]}` or
`{authors:[self]}` filters — author self-reads bypass the gate and are
unaffected.
## Gates
`just check` ✅ | `just test-unit` ✅ | `cargo test -p buzz-relay` ✅ (749
passed, 1 pre-existing failure in
`demo_join_forwarded_arm_round_trips_echo` — flaky on `main`, unrelated
to this PR, verified red at `origin/main` before this branch)
---------
Signed-off-by: Will Pfleger <pfleger.will@gmail.com>
Co-authored-by: npub1mn7jgtj4w2pd0g0zeuhxsa6jy6p0rewxz4kujt98my82ahfmp72sxjexk7 <dcfd242e557282d7a1e2cf2e6877522682f1e5c6156dc92ca7d90eaedd3b0f95@buzz.block.builderlab.xyz>
