diff: the pane notices a finished merge by itself, and stays quiet on an unusual branch name - #98357

poteat's HEAD watch from the pin, quiet polling on unusual branch names,
and the /clear shown mark, fitted into the bundle's ownership model:

- register(): poteat's doc wording, with anthropics#94847's in-tree fetch clause kept.
- probeBackend: startPoll runs right after the pin, as poteat's does after
  `backend ??= probed`. Here the pin follows the owner check, so a probe
  overtaken while it reads the store starts no watch.
- refresh: a listed read no longer starts the poll (poteat).
- placePane: poteat's keepBaseline() on open. The shown mark stays with the
  bundle's recordShown, which is fenced by epoch and close.
- openOnRestore: the bundle's epoch guard is kept. poteat's change there
  only restyles the same read.
- /clear under an open pane (confirmSessionChange): the pane counts as shown
  for the new conversation with trigger 'manual', and its HEAD baseline is
  kept after the pin (poteat's two additions).
- register.test.ts: anthropics#94847's resumed-session test is kept, and poteat's
  retitle is taken.

Co-authored with a harness running Claude and Codex teams.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
Claude-Session: 16cb7844-98c6-4af7-b67a-3e9d16705e7f

anthropics#98357's keepBaseline() read HEAD outside the bundle's 'head' lifecycle.
While earlier HEAD reads were held, each /clear under an open pane
started another git process: 6 and 12 reads where the capacity tests
allow 3. The baseline read now runs as 'head' work. It shares a poll's
read, waits for capacity, and does not start once the pane is hidden.

Tests:
- owner-lifecycle: the four HEAD-count tests also count the baseline
  read at each open and each /clear. Without the two keepBaseline()
  calls they read the bundle's former counts.
- register: poteat's /clear shown test switches sessions through
  Fixtures.switchSessions. Like the bundle's other /clear tests since
  5d5f379, it now ends the old session before the ID changes.

Co-authored with a harness running Claude and Codex teams.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
Claude-Session: 16cb7844-98c6-4af7-b67a-3e9d16705e7f

poteat's batched hunks read (one git child for every drawn file), fitted
into the bundle's body ownership:

- fetchBodies: each call reads its new rows with one
  pinned.fetchHunks(data, files) run through lifecycle.runBody. A read
  skipped before it starts is not a Git failure. Its answer is shown only
  while its owner and stamp are current. bodyLoads becomes anthropics#98445's set of
  asked paths.
- Lifecycle: one body read per view at a time, two across views as
  before. BODY_FETCH_CONCURRENCY, which anthropics#98445 deletes, set the old
  per-view limit.
- fetchHunks takes an optional isWanted, and a read that can no longer be
  shown starts no further child for the paths past MAX_PATHSPEC_CHARS or
  left unread by a cut answer. Without it, a split read released after
  /clear or a base switch started its second child for the ended view.
- register() doc and openOnRestore: the bundle's text and epoch guard, as
  in the anthropics#98357 merge.

Tests:
- owner-lifecycle: the three BODY_FETCH_CONCURRENCY tests count batched
  children, and the lifecycle world records every asked path. The skip
  test now queues its refresh's batch behind two held batches, so /clear
  skips it. New: a split read revoked by /clear or a base switch starts
  no further child.
- fetch-hunks: a read no longer wanted asks no further child.

Co-authored with a harness running Claude and Codex teams.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
Claude-Session: 16cb7844-98c6-4af7-b67a-3e9d16705e7f

main now has poteat's anthropics#98374, anthropics#98445 and anthropics#98357 as squash commits
(9778ad7, 292c5b8, 525d3b3). Its mods/ is identical to 732e167
with the three PR heads merged, which this bundle has already merged
from the heads. The six files that conflict keep the bundle's text from
the first parent, so mods/ is unchanged by this merge. CHANGELOG.md and
feed.xml come from main.

Co-authored with a harness running Claude and Codex teams.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
Claude-Session: 16cb7844-98c6-4af7-b67a-3e9d16705e7f