pi extension: identify the pane from TMUX_PANE

the extension asked tmux for "the current pane", which resolves to the
session's active pane, not the pane pi runs in, so agents in background
windows reported their state onto another pane. tmux sets TMUX_PANE for
every process it starts in a pane; use it.

e2e step 12 loads the shipped extension with a fake pi from a pane that
is not its session's active pane and asserts the report lands there; it
fails against the previous extension. hook reports log at info again.

rebuild the status model as herdr's state machine, event-driven and tested

the seen logic was inverted: first observations were marked done and real
completions idle, so the menu showed teal for agents that did nothing and
green for agents that finished, and attending changed nothing visible.

- watcher::advance is herdr's apply_pane_state_change + mark_active_tab_seen
  as a pure function, unit-tested against herdr's own cases; attendance is
  window-level like herdr's active tab
- hook reports are events applied in order, so a turn shorter than a poll is
  still a completion
- event-driven: hook reports, dingger focus, and tmux focus hooks wake the
  watcher; notifications are delivered off-thread (the macos call blocked
  ticks for 2+ seconds) after the pane options are written
- all per-pane state persists in tmux pane options, so restarts and deploys
  lose nothing, including the authoritative hook state
- every click goes through dingger focus: the menu bar shells out to it and
  the status-line binding runs it; it picks the right client, skips the
  window already shown, and activates the terminal app hosting the client
- the ready queue is ordered like the menu (blocked first, then oldest done)
- menu bar and tmux segment render herdr's symbols in herdr's palette
- tests/e2e.sh: 60 assertions against an isolated tmux server with a real
  client, a 30s poll interval, and a slow fake notifier

write @agent_state on attendance changes, not just transitions

the seen demotion (done -> idle when the user focuses the pane) only
updated the daemon's internal track; @agent_state stayed done forever,
so the menu bar and status line never reflected attendance. the display
status is now written whenever it differs from the pane option,
regardless of what triggered it.

adopt herdr's five-status model with symbols style and focus detection

statuses are now herdr's verbatim: working (yellow), blocked (red),
done (teal, finished and unattended), idle (green, attended since its
last transition), unknown (gray) - priority blocked > done > working >
idle > unknown. the daemon watches tmux focus (pane_active of attached
clients) to mark panes attended, which is what separates done from idle.
menu bar renders symbols-style glyphs with herdr's colors in priority
order; the tmux segment stays after the clock and renders done/blocked/
working counts from numeric options. deployment note: do not strip the
binary - it invalidates the ad-hoc signature and macOS kills it on
launch.

menu bar: herdr-style colored state glyphs; tmux segment before the clock

the design panel's monochrome template rendering made every row look
alike; restore herdr's agent-panel visual language - green ready, yellow
working, red blocked, filled when unseen in the queue. the tmux segment
moves left of the clock so it is visible at a glance; the status item
logs what it observes for diagnosis.

menu rows show window names, not indexes

display target is session:window-name (pane index only when split);
switching keeps using the pane id. add --print debug mode to inspect the
rendered rows without opening the menu.

ready-queue fifo with click-to-focus; redesign presentation per design panel

daemon tracks when each agent became ready (idle/blocked, unacked) and
publishes fifo queue + numeric counts as server-global options; unknown
to idle transitions stay out of the queue (restart spam). new dingger
focus subcommand jumps to the longest-waiting pane and acks it, bound to
status-right clicks in tmux. menu bar redesigned per two-model design
panel: monochrome sf-symbol bell + queue depth, queue-ordered rows with
state glyphs and right-aligned targets, row clicks ack like focus does.
tmux segment renders glyph+count with a single red accent for blocked;
fixes unescaped comma in the conditional format that truncated the
segment entirely.

menu bar app: live agent states from tmux pane options

single-file appkit status item (menubar/main.swift, LSUIElement) polling
@agent/@agent_state pane options every 2s: counts in the bar, per-pane
rows with click-to-focus via switch-client. daemon now also writes an
@agent label per pane so the menu bar and tmux status-right can render
agent names without duplicating identification logic.

wait for tmux at startup, force utf-8 for tmux clients, add launchd packaging

running under launchd, the tmux client defaults to the c locale, which
makes tmux mangle tab-separated -f output into underscores, so every
pane parsed as one field and the watcher silently saw nothing; invoke
tmux with -u so format output is locale-independent. drop the startup
fail-fast: the watcher now waits for a tmux server and attaches when one
appears, which is the right shape for a login agent. ship the launchd
plist under packaging/launchd.

initial dingger: tmux agent watcher with herdr's detection engine

extract detect-core from herdr's src/detect (engine + 22 manifests,
tests unchanged) and add the dingger binary: tmux capture-pane watcher,
process-tree agent identification, herdr's notification policy, embedded
notification sounds, @agent_state write-back, and catalog-based manifest
refresh. viewer screens are non-observations per the engine contract;
reviewed by a three-model panel (opus 5.5, gpt 6.1 sol, kimi k3) with
all confirmed findings applied as deletions.