feat(gateway): add LINE quick reply approvals

[aaronlin]

What does this PR do?

Adds LINE quick-reply prompts for gateway approval flows, while keeping the actual decision payloads on the existing slash-command path.

LINE users now get quick replies for dangerous command approvals and destructive slash confirmations. The visible labels are localized through Hermes i18n (display.language) with LINE-specific overrides via LINE_LANGUAGE, LINE_LOCALE, extra.language, or extra.locale. The quick-reply message text remains stable (/approve, /approve session, /approve always, /deny, /always, /cancel) so the gateway's existing approval handlers continue to resolve the flow.

This PR intentionally does not include the LINE media enum fix; that is split into #35681 to keep both PRs focused.

Related Issue

No issue filed.

Related prior PRs found during duplicate search:

• feat(line): inline-button approval prompts (Allow Once / Session / Always / Deny) #23581: closed/unmerged earlier LINE approval button attempt.
• feat(line): inline-button approval prompts (Allow Once / Session / Always / Deny) #29053: open/stale earlier LINE approval button attempt using template buttons and postback dispatch.

This PR differs by using LINE Quick Reply message actions that feed the existing slash-command approval path, plus locale-aware labels and focused adapter tests.

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 🔒 Security fix
• 📝 Documentation update
• ✅ Tests (adding or improving test coverage)
• ♻️ Refactor (no behavior change)
• 🎯 New skill (bundled or hub)

Changes Made

• plugins/platforms/line/adapter.py
  • Added quick-reply message construction helper.
  • Added LINE send_exec_approval() support for dangerous command approvals.
  • Added LINE send_slash_confirm() support for destructive slash confirmations.
  • Added shared pre-built LINE message-object send helper with reply-token-first behavior and push fallback.
  • Added LINE locale override resolution.
• plugins/platforms/line/plugin.yaml
  • Added optional setup metadata for LINE_LANGUAGE and LINE_LOCALE.
• locales/*.yaml
  • Added gateway.line_quick_reply.* labels across all locale catalogs.
• tests/gateway/test_line_quick_reply.py
  • Added coverage for reply-token usage, push fallback, quick-reply slash payloads, and Traditional Chinese labels.

How to Test

1. Run syntax checks:
   • python3 -m py_compile plugins/platforms/line/adapter.py tests/gateway/test_line_quick_reply.py agent/i18n.py
2. Run diff hygiene:
   • git diff --check
3. Confirm locale/setup coverage:
   • rg -l "line_quick_reply:" locales
   • rg -l " deny:" locales
   • rg -n "LINE_LANGUAGE|LINE_LOCALE" plugins/platforms/line/plugin.yaml
4. Run the targeted regression test:
   • scripts/run_tests.sh tests/gateway/test_line_quick_reply.py
5. Optional broader gateway coverage:
   • scripts/run_tests.sh tests/gateway
6. In CI or a complete local dev environment, run the full suite:
   • pytest tests/ -q

Note: Full pytest tests/ -q was not completed locally. Broader gateway coverage was attempted and has one unrelated local failure in tests/gateway/test_shutdown_forensics.py::TestSpawnAsyncDiagnostic::test_spawns_subprocess_and_writes_output.

Checklist

Code

• I've read the Contributing Guide
• My commit messages follow Conventional Commits (fix(scope):, feat(scope):, etc.)
• I searched for existing PRs to make sure this isn't a duplicate
• My PR contains only changes related to this fix/feature (no unrelated commits)
• I've run pytest tests/ -q and all tests pass
• I've added tests for my changes (required for bug fixes, strongly encouraged for features)
• I've tested on my platform: macOS local checkout; targeted LINE quick-reply test passed; gateway suite attempted with one unrelated shutdown-forensics failure

Documentation & Housekeeping

• I've updated relevant documentation (README, docs/, docstrings) — or N/A: updated plugins/platforms/line/plugin.yaml setup metadata
• I've updated cli-config.yaml.example if I added/changed config keys — or N/A: N/A, LINE plugin setup metadata is in plugin.yaml
• I've updated CONTRIBUTING.md or AGENTS.md if I changed architecture or workflows — or N/A: N/A
• I've considered cross-platform impact (Windows, macOS) per the compatibility guide — or N/A: pure Python adapter/i18n changes, no platform-specific primitives
• I've updated tool descriptions/schemas if I changed tool behavior — or N/A: N/A

Screenshots / Logs

N/A. Local checks run on this branch:

python3 -m py_compile plugins/platforms/line/adapter.py tests/gateway/test_line_quick_reply.py agent/i18n.py: passed
git diff --check: passed
rg locale/setup checks: passed
scripts/run_tests.sh tests/gateway/test_line_quick_reply.py: 4 passed
scripts/run_tests.sh tests/gateway: 6062 passed, 1 unrelated failure

Failure:
tests/gateway/test_shutdown_forensics.py::TestSpawnAsyncDiagnostic::test_spawns_subprocess_and_writes_output
assert pid is not None and pid > 0

[teknium1]

Thanks for the focused LINE UX improvement. Current main still has no LINE send_exec_approval or send_slash_confirm override (plugins/platforms/line/adapter.py:1079-1146), so the feature remains useful.

Problems

• plugins/platforms/line/adapter.py:1139-1140 emits /always and /cancel, but neither is a registered command (hermes_cli/commands.py:64-255). should_bypass_active_session() only bypasses resolvable commands (hermes_cli/commands.py:388-408), so an active session queues these replies before the slash-confirm interceptor at gateway/run.py:9127-9153 can resolve them.
• The new direct-send path at plugins/platforms/line/adapter.py:1197 leaves a current slow-response _pending_buttons entry live. LineAdapter.send() then caches the next normal response instead of delivering it (plugins/platforms/line/adapter.py:1095-1102). The new test fixture omits _pending_buttons and _cache (tests/gateway/test_line_quick_reply.py:33-38), so it misses this interaction.

Suggested changes

• Make pending slash-confirm replies bypass active-session routing generically, including Always and Cancel, and test all three quick-reply choices during an active session.
• Define and test the slow-response-cache interaction so approval acknowledgement and final output remain deliverable.

Automated hermes-sweeper review.

[teknium1]

/always and /cancel are not registered slash commands on current main, so should_bypass_active_session() returns false. When the session is active, BasePlatformAdapter queues these replies before the runner's slash-confirm interceptor can see them; the Always and Cancel chips need a generic active-session dispatch path or a callback-based flow.

[teknium1]

This direct path does not clear an existing LINE _pending_buttons slow-response cache entry. On current main, the acknowledgement/final response subsequently sent through send() is cached instead of delivered. Handle that state and add coverage with _pending_buttons plus _cache initialized.