Import Codex CLI tab-status (gnachman/iTerm2#673), gated behind spawnterm.codex_status

[carvalhoviniciusluiz]

Closes #60

Summary

Imports upstream gnachman#673 ("Show Codex CLI activity in tab status") into the fork, gated behind a new spawnTerm feature flag so it is OFF by default.

Codex (OpenAI) does not emit iTerm's OSC 21337 status protocol; it signals working/idle state by prefixing the OSC 0/1/2 terminal title with a braille-spinner glyph while crunching and dropping it when idle. This PR:

• Adds a pure decoder (CodexTitleStatusDecoder) for the braille-spinner title prefix (U+2800–U+28FF + space), and a foreground-job-gated adaptor (CodexTitleStatusAdaptor) that synthesizes the equivalent iTermSessionTabStatus (Working/Idle) only when codex is the foreground job.
• Introduces a new Title Changed event-trigger category (iTermTriggerMatchTypeEventTitleChanged) with an optional titleRegex filter, selectable/configurable like the other event triggers.
• Adds an always-on built-in Codex Status trigger (CodexStatusTrigger) seeded by EventTriggerEvaluator, riding the Title Changed event; its side effect flows through a new triggerSession:applyCodexTitleStatusWithTitle: delegate method (VT100Screen / VT100ScreenMutableState) to -[PTYSession screenApplyCodexTitleStatusWithTitle:].
• Synthesized status carries a source tag so it never overwrites a real OSC 21337 emitter and is excluded from window-restoration arrangements.

Feature flag (default OFF)

New capability spawnterm.codex_status ("Codex Tab Status"), added in all three synced places — spawnterm/flags/spawnterm-flag, spawnterm/flags/spawnterm_flag.py, sources/Settings/iTermSpawnTermCapabilities.m — plus spawnterm/docs/feature-flags.md. Toggled in Settings → General → AI → spawnTerm. Shell/Python parity tests (test_flags.sh) stay green (26/26).

Gate point: the Codex-activity → tab-status behavior is gated at the single choke point -[PTYSession screenApplyCodexTitleStatusWithTitle:] on isEnabledForCapability:@"codex_status". Both the trigger callback path and the foreground-job-change path funnel through it, so OFF ⇒ no synthesized Codex tab-status side effects (stock behavior).

Conflict resolution (this is the most invasive import — edits iTerm2 core)

• PTYSession.m — our prior Tier 4.C — user-var sidecar persistence (fork-direct) #51 (user-var sidecar: screenSetUserVar:, userVarSidecar, replay, GC, dealloc) and Tier 4.A — optional delivery ack on async_send_text (fork-direct) #49 (writeTask:completion: threading) changes are fully preserved; verified present post-merge. The Show Codex CLI activity in tab status gnachman/iTerm2#673 hooks are purely additive (a call in setCurrentForegroundJobProcessInfo:, the trigger fire in screenSetWindowTitle:, and the new screenApplyCodexTitleStatusWithTitle: method).
• Trigger.h — added the triggerSession:applyCodexTitleStatusWithTitle: delegate declaration alongside existing ones; no conflict with fork additions.
• ITAddressBookMgr.h — new enum member landed as iTermTriggerMatchTypeEventTitleChanged = 116 (fork already had …VariableChanged = 115, no collision).
• Applied via the squashed net diff (gh pr diff 673) to avoid the 4-commit series' internal churn (the PR reworks its own initial hook onto the trigger system). Hand-fixed rejects in iTermEventTriggerEvaluator.swift and iTermSessionTabStatus.swift (fork context drift: our fork uses RLog, has backgroundTasks/broadcastsChanges additions) preserving all fork code. New Swift files registered via tools/add_file_to_xcodeproj.rb into iTerm2SharedARC; ModernTests auto-included via the synchronized group.

Build status (HONEST)

Not verified as a green build — the environment cannot compile iTerm2. tools/build.sh aborts in the dependency phase, before any target sources compile, with:

Companion/CompanionCore/Sources/CNoise/shim/cnoise_stubs.c:27:10: error: 'noise/protocol.h' file not found (in target 'CNoise' from project 'CompanionCore')

This is the known toolchain/submodule mismatch (Xcode 26.2 vs prebuilt-deps 26.5), unrelated to these changes. The change set was verified correct-by-inspection: PTYSession.m preserves #51+#49 and adds gnachman#673; every imported symbol resolves against the fork (iTermSessionTabStatus(sessionID:), hasActiveStatus, apply(_:), maybePostTabStatusNotificationWithPreviousStatusText:, sessionTabStatusDidChange:, iTermVariableKeySessionForegroundJobAncestors, the Trigger scheduler API, iTermTriggerMatchTypeEventTitleChanged); no .rej/leakage; no submodule/ThirdParty/version-stamp changes.

Provenance

Adapted from upstream gnachman#673.

🤖 Generated with Claude Code

[carvalhoviniciusluiz]

Review by tech-lead — code APPROVED by inspection; build UNVERIFIED (environment).

Import mais invasivo (upstream gnachman#673). Boa decisão: usou o net diff squashado (a série de 4 commits se sobrescrevia). Verifiquei o merge crítico em PTYSession.m:

• Tier 4.C — user-var sidecar persistence (fork-direct) #51 sidecar intacto: userVarSidecar×10, replayUserVarSidecar×3, screenSetUserVar write-through×1.
• Tier 4.A — optional delivery ack on async_send_text (fork-direct) #49 intacto: writeTask:completion:×2.
• Show Codex CLI activity in tab status gnachman/iTerm2#673 adicionado: screenApplyCodexTitleStatusWithTitle×3, hooks no foreground-job + title-changed trigger.
• Rejects resolvidos à mão (RLog↔DLog no evaluator; State da fork com backgroundTasks/broadcastsChanges no iTermSessionTabStatus). Enum novo 116 (sem colisão com 115).
• Flag spawnterm.codex_status (default OFF) em shell+py+capabilities + docs; parity 26/26.
• Gate: choke point único screenApplyCodexTitleStatusWithTitle: com early-return ![... isEnabledForCapability:@"codex_status"] → OFF = stock.
  Higiene limpa (inclui VT100Screen{,.MutableState,Delegate} legítimos do Show Codex CLI activity in tab status gnachman/iTerm2#673). Proveniência: Adapted from upstream Show Codex CLI activity in tab status gnachman/iTerm2#673. Build não verificável aqui (CNoise). Sem ressalvas.