Port upstream batch 2: away-mode reliability (#54) + Claude ghost text (#59)

[augustomklee]

What

Second batch of the cherry-pick-and-port of upstream into this psmux/Windows fork: the two supervision-reliability fixes, hand-adapted (every tmux rewired to $FM_MUX; doc deltas folded into CLAUDE.md, not AGENTS.md).

New: bin/fm-tmux-lib.sh

One shared set of pane primitives - busy detection, border- and ghost-text-aware composer-empty detection, and a verified Enter-retry submit - sourced by both the away-mode daemon and fm-send.sh so the logic can't drift. Ported from upstream with tmux → $FM_MUX; it sources fm-mux-lib.sh so it works standalone.

kunchenguid#54 (e4fbed5) — harden away-mode escalation delivery

• Border-aware detection: strips the harness's box-drawing borders before deciding, so an idle bordered claude composer (│ > … │) reads empty, not pending. Root cause of incident afk-invx-i5, where away-mode deferred 100% of escalations for 9.5h.
• Max-defer escape: anything buffered past FM_MAX_DEFER_SECS (default 300) gets one more flush; if delivery still can't be confirmed, a rate-limited wedge alarm fires (ERROR log + state/.subsuper-inject-wedged marker + status-line flash). The daemon can no longer silently wedge.
• Verified submit via the shared primitive; fm-send.sh exits non-zero on a positively-confirmed swallow, so a steer that doesn't land is no longer silent.

kunchenguid#59 (3718fd0) — ignore Claude predicted-prompt ghost text

• At the source: claude crewmates launch with CLAUDE_CODE_ENABLE_PROMPT_SUGGESTION=false (per-launch env prefix in fm-spawn.sh, scoped to firstmate-launched agents; never the captain's global config).
• Defense in depth: fm_tmux_strip_ghost drops dim/faint (SGR 2) runs from the captured cursor line, so ghost text never reads as pending input.

The fork kept its pane primitives inline in the daemon; this replaces them with the shared lib's fm_pane_is_busy / fm_pane_input_pending and routes the inject submit through fm_tmux_submit_core.

Tests

• New tests/fm-composer-ghost.test.sh (ported, FM_MUX-pinned to the fake): dim-ghost stripping incl. SGR color payloads, dim-only/bordered composers read not-pending, real and colored text still pending. Passes 8/8 locally.
• Not ported: upstream's additions to tests/fm-wake-queue.test.sh and its fm-peek escape-free test - they lean on the FM_HOME / FM_ROOT_OVERRIDE scaffolding introduced by the secondmate rewrite (feat: support persistent secondmates kunchenguid/firstmate#37), which this fork is not taking. The existing wake-queue suite is unchanged.
• Note on local runs: tests/fm-wake-queue.test.sh aborts early on this Windows/MSYS dev machine at a background-process watcher timing test (watcher did not exit for first signal) - confirmed identical on unmodified main, so it is pre-existing and platform-related, not caused by this change. CI (Linux) runs the full suite.

Verification

• bash -n passes on all touched scripts.
• fm_tmux_strip_ghost validated directly: dim-only → empty, normal/bold/colored text preserved, bordered-dim → borders only (then stripped).
• Zero raw tmux calls introduced (all routed through $FM_MUX).

Docs

CLAUDE.md (sections 2/4/8), README.md, and the afk SKILL.md updated for the shared lib, border/ghost-aware detection, the max-defer wedge alarm, and the new env knobs (FM_MAX_DEFER_SECS, FM_SEND_*, FM_INJECT_CONFIRM_*).