Ds/put 1674 (#3715)

* feat: app-scoped share listing and revoke surface (PUT-1670)

* fix: address review on app-scoped share surface

- Scope the uid-addressed revoke to the named row: only that row's
  issuer's grant is withdrawn, and only that one invite cancelled —
  an app or owner addressing one row no longer takes another issuer's
  grant on the same (item, recipient) pair with it.
- Delete a pending row directly on uid-addressed revoke, so an invite
  whose address registered but never claimed can still be withdrawn.
- Read the legacy `issuerAppUid` data key in the SQL app filter and
  grouping, alongside the unified `issuedByApp`.
- Refuse malformed `appUid` input (duplicated param, empty string)
  instead of silently listing everything, and refuse app-listing
  cursors that decode but name no appUid.
- Derive the acting app from `effectiveApp` alone, per the actor
  contract; drop the second derivation site.
- Pin the attribution semantics with tests: one row records one
  issuance, so re-sharing the same pair re-attributes it to whoever
  issued last, in both directions.
- Soften the uniform-404 docblocks to what the gates actually answer.

* feat: readable grant audit trail (PUT-1674)

* fix: cover the apps summary's no-app-group first page (PUT-1670)

listOutboundApps sorts the no-app group first via an empty-string
sentinel. Add a regression test pinning that a first page (no cursor)
actually returns it, and that the cursor it hands back resumes past it
into the app-keyed groups rather than skipping or repeating.

src/docs/src/FS/listSharedByMe.md

@@ -27,6 +27,7 @@ An object with the following properties:
 - `limit` (Number) - Maximum shares per page.
 - `cursor` (String) - Continuation token from a previous page.
 - `includeTotal` (Boolean) - Include the total count in the response. Defaults to `false`.
+- `appUid` (String) - Narrow the listing to the shares one app issued in your name, or pass `'none'` for the ones you made yourself. An app calling this is bound to its own grants whatever it asks for.
 
 ## Return value