<!-- Draft PR body for #7385 · fix(mobile): bind same-name mentions to
exact selected identities · https://github.com/block/buzz/pull/7385 -->
🤖
## Summary
If two people in a channel share a display name, mobile couldn't tell
them apart in mentions: picking the second could overwrite the first's
selection, a rendered mention linked whichever same-name person matched
first, and a later rename or a shorter name could re-bind the text to
the wrong recipient. This PR binds every mention to the exact selected
identity:
- Each same-name selection keeps its own recipient instead of
overwriting by name; conflicting picks get a qualified label like `Name
(key…)`.
- The longest matching label wins, so a shorter or interior name can
never claim part of a longer one and steal its identity.
- Rendering resolves recipients by the signed identity key from the
event's tags — never from message text alone — so qualified labels stay
correct regardless of tag order and survive later renames; an untagged
ambiguous label blocks shorter mentions instead of silently re-binding.
Ports the landed Desktop exact-recipient behavior (see
`docs/mention-editor.md`).
### Related issue
- Fixes: N/A. No mobile issue; Desktop's landed exact-recipient fixes
are the reference this ports.
- Independent base (`main`). #7387 (child) persists these exact
selections in saved drafts.
- Landing note: branches in this series overlap in the composer — when
rebasing, keep exact/durable mention bindings, the explicit
invite/reference-only choice, the account/visit/revision fences, and
authorization before membership preparation and publication; don't
resolve conflicts by taking either side wholesale.
- Draft — not requesting merge yet; the security advisory run for this
range timed out without results (no verdict).
### Testing
- Regressions cover same-name collisions, prefix/overlap, removal, tag
order, and renames.
- At `acd841354a692243f1cb4c04059baad42f1d2abb`: `just mobile-check` and
full `just mobile-test` pass (2,082 tests). The earlier full `just ci`
receipt linked below is reused only for unchanged non-mobile
code/tooling, not claimed as a rerun at this head.
- Previous-head evidence: `just mobile-check`, the full mobile test
suite, and full local `just ci` all pass — receipts in the [exact-head
evidence
comment](https://github.com/block/buzz/pull/7385#issuecomment-5574635836).
- Verification is widget-test level; no native device or simulator run
is claimed.
To see it: mention two teammates with the same display name — both stay
distinct, the second shows a qualified label, and the rendered message
keeps both correct even after either renames.
### Screenshots
Flutter production-widget test renders — not native-device screenshots
or acceptance captures.
| Scenario | Before | After |
|---|---|---|
| Qualified mention chip for same-name recipients, at 200% text scale
(deliberate stress fixture) | 
| 
|
<details>
<summary>Capture provenance</summary>
Rendered by the Flutter widget engine in a `flutter test` run
(production widgets, production theme; no device or simulator). Before:
this PR's declared base `3c7f288c60d67df78577b237e27c3dfc8831aaa1`.
After: its head `39afd73b0adfde14164f4b10dbd089cb498312b6`.
</details>
Signed-off-by: Logan Johnson <loganj@squareup.com>
🤖
## Summary
In the mobile app, anyone who hasn't set a display name shows up as a
raw 64-character hex key (e.g. `3a5d4f9c…`) — unreadable, and
unrecognizable as the same identity across screens. Profile and Settings
also let you copy that raw hex. Nostr public keys have a standard
readable form — `npub1…`, the same encoding other Nostr apps and our
desktop app already display. This PR makes every mobile identity surface
render npub instead:
- **Unnamed people everywhere** — message and thread authors, reactions,
typing indicators, member lists, channel details, DM headers and tiles,
inbox, search, forum cards, Pulse notes and reply context, mention
suggestions, and invite rows — now show a compact npub label: first 8 +
last 4 characters of the full npub joined by an ellipsis
(`npub1abcd…wxyz`), the same truncation desktop uses. Previously these
showed truncated raw hex.
- **DM fallback avatars and blank names** — 1:1 DM tiles and headers key
their fallback avatar to the same non-self counterpart the label names,
including self-first participant order; a self-DM keeps its
hex-key-derived initial. Blank or whitespace-only display names fall
back to the compact npub instead of rendering empty, while nonblank
authored names render verbatim (padding included).
- **Profile sheet → "Copy public key"** now copies the full canonical
npub — never raw hex. When the identity string isn't a valid public key,
the copy tile is disabled, so a malformed key never reaches the
clipboard.
- **Settings → Identity (pubkey)** displays and copies the full npub; an
invalid identity reads "Identity unavailable" with copy disabled.
- **Invalid identities never leak truncated raw hex** into the UI
anywhere — they render a neutral "Unknown identity" label.
- **Unchanged on purpose:** display names and verified handles (NIP-05 —
the `name@domain` badge) still render as before. Unnamed avatars keep
distinct per-key initials, derived from the underlying hex key rather
than the npub — otherwise every unnamed key would render the same "N"
initial. Event IDs are not public keys, so they keep their hex
truncation (in Pulse's "Replying to", the parent author shows npub while
an event-id fallback still shows hex). The nevent share link, private
keys, and internal hex storage are untouched. Inputs that accept a key
(invite/member entry) accept both hex and npub and keep working in hex
internally.
### Related issue
N/A. Searched open issues/PRs for npub identity display on mobile —
closest related: none found. Desktop's parallel npub standardization
lives in the stacked desktop PRs (#7488 foundation, #7489 controls,
#7495 display surfaces); this is the independent mobile slice (based
directly on `main`, not on those branches).
### Testing
At exact head `5a620e420a1fd57d9d8011ac26434eed32fcf765` (base: `main`
`44316ff72`; 40 files, +1,345/−154):
- Full mobile suite: 2,098 tests passing (`cd mobile && flutter test`);
`flutter analyze` clean; `dart format --set-exit-if-changed .` clean —
the same checks CI runs.
- Widget/unit coverage at production seams: compact labels and hex-keyed
avatar initials for DM headers/tiles, member rows, mention suggestions,
and Pulse reply context; DM fallback avatars keyed to the labeled
counterpart (self-first order and self-DMs); blank/whitespace
display-name npub fallback with nonblank authored labels verbatim,
including the Activity inbox sender and profile-sheet heading (each with
its own empty/whitespace production-seam regression); full-npub copy and
disabled-copy semantics in profile and settings; invalid-key
suppression; and hex↔npub input round-trips.
Verified via unit and widget tests — no device/simulator validation is
claimed.
### Task provenance
Buzz channel: `1f0e4a3d-7e01-4efe-bb16-843b357f85c9`
Task:
buzz://message?channel=1f0e4a3d-7e01-4efe-bb16-843b357f85c9&id=86b34eb4bd84a1472419e9af22636c011c0fe273e3c196f967d7a36996e149b6
---------
Signed-off-by: Logan Johnson <loganj@squareup.com>
Co-authored-by: Larry <627498bd4bd1f281a16431e3c6cce3b5c25b6692798c78672298aefbf2f8f8b5@buzz.block.builderlab.xyz>
