* fix(mobile): keep repeated-prefix chat replies streaming
Text alone can't tell "the transcript caught up with this stream" from
"a new reply repeats the previous turn's prefix", so the old suppress-on-
prefix rule swallowed genuine repeated replies. A stateful gate remembers
which transcript tail predates the current stream segment and hides the
bubble only when that tail moved during the segment, scoped to the active
host/workspace/tab/session so a swapped chat can't inherit a baseline.
Refs STA-3333.
* fix(mobile): keep the streaming gate alive across chat/terminal toggles
The gate lived in MobileNativeChatView, but MobileNativeChatOverlay returns
null whenever the user peeks at the terminal — that unmounts the view and
throws the baseline away, so the repeated-prefix reply was swallowed again on
the way back. Move the gate (and the fold memo it reads) up to the overlay,
which stays mounted across those toggles.
While hidden the transcript is empty and the throttled stream reports no text,
which the gate would have read as "idle" and re-anchored on. Pass the agent's
working state so a textless tick inside a live segment holds the baseline
instead. The scope key is now keyed off the tab rather than the view-gated
chat resolution, so it survives the toggle too; streamIdentity keeps its exact
previous value because the delayed-send guards compare against it.
Also drops a dead disjunct in the caught-up test: a null baseline is already
unequal to every real tail id.
* test(mobile): model the real re-show ordering in the streaming-gate tests
The overlay regression test replayed the transcript before the stream text on
the way back from the terminal view. That ordering is backwards: the session
withholds `messages` until a fresh read settles (an RPC round trip) while the
throttled stream text returns in ~50ms — and with the transcript already back,
a gate that got discarded on the toggle still passes. Replay the real order,
which pins the gate's lifetime as intended.
Swaps the hidden-gap duplicate case for the in-view one (a tool frame clears
the assistant text mid-turn), which is where the hold actually earns its keep;
the hidden-gap direction stays covered at the gate level.
* fix(mobile): stop the streaming gate adopting a reply as its own history
A textless status tick was re-anchoring the gate's pre-stream baseline, so
two paths still rendered wrong:
- The reply's transcript push beats its throttled status text whenever the
pane stays `working` past the turn (a live subagent or background task).
The tick in between adopted the just-landed reply as history, and the
status text that followed rendered it a second time — a duplicate bubble,
and a regression against main's suppress-on-prefix rule.
- Peeking at the terminal between turns empties the transcript. That empty
tail was adopted as the baseline, so the next repeated-prefix reply was
swallowed again — the bug this PR exists to fix.
Only a tick that carries a real tail and sits outside a live turn anchors
now, with an exception for a gate that has never anchored: mounted mid-turn,
the first real tail it sees is the best history it will ever get.
Also drop `buildMobileNativeChatData`, a test-only builder this PR had wired
the new gate into; its green test asserted the exact suppression this PR
removes. Its fold/pending/image coverage moves to the builder the view calls.
* test(mobile): pin the textless anchor's text reset
Mutation testing found the `prevText` reset on an anchoring textless tick
unpinned: keeping the previous turn's text there reads the next turn's
opener as a new segment, re-anchors onto the reply that just landed, and
renders it a second time — the same duplicate-bubble class already fixed
twice on this branch.
Brennan Benson