feat: add vi mode detection and insert-mode prefix for tmux send-keys

[xukai92]

Closes #1365

Changes

• Add _detect_vim_mode() to factory/runners/_tmux_persist.py — reads ~/.claude/settings.json and returns True when editorMode is "vim", with graceful fallback to False on missing file, malformed JSON, or any OSError
• Add _tmux_send_enter() helper that uses the two-step hex approach (text then -H 0d) and optionally prefixes with Escape → 100ms sleep → i when vim_mode=True to ensure insert mode
• Update run_in_tmux() to detect vim mode once at function start and pass it through to all _tmux_send_enter() calls
• Update docs in factory/agents/prompts/refactory.md and factory/agents/skills/sessions.md to document the two-step hex approach and vi mode handling
• Add 6 new test cases: TestDetectVimMode (4 cases) and TestTmuxSendEnterVimMode (2 cases), plus updates to all existing run_in_tmux tests for the new send-keys pattern

[github-actions]

Sentrux Quality Report

Absolute

Scanning ....
[scan] git ls-files: 635 total, 621 kept, 14 dropped (ext:14, meta:0, big:0)
[build_project_map] 621 files, 107 unique dirs, 99 cache misses, 6.1ms
[resolve] 1158 resolved, 1548 unresolved (of 2706 total specs)
[resolve_imports] project_map 6.3ms, suffix_idx 1.2ms, suffix_resolve 17.8ms, total 25.2ms
[build_graphs] 621 files | maps 2.5ms, imports 25.4ms, calls+inherit 6.2ms, total 34.0ms | 1157 import, 8687 call, 2 inherit edges
sentrux check — 3 rules checked

Quality: 4470

✗ [Error] max_cc: 3 function(s) exceed max cyclomatic complexity of 30
    factory/cli/_ceo_helpers.py:_validate_ceo_flags (cc=43)
    factory/cli/_ceo_helpers.py:_execute_ceo (cc=43)
    factory/cli/run.py:cmd_run (cc=32)

✗ 1 violation(s) found

Diff (vs base branch)

Scanning ....
[scan] git ls-files: 635 total, 621 kept, 14 dropped (ext:14, meta:0, big:0)
[build_project_map] 621 files, 107 unique dirs, 99 cache misses, 6.1ms
[resolve] 1158 resolved, 1548 unresolved (of 2706 total specs)
[resolve_imports] project_map 6.3ms, suffix_idx 1.1ms, suffix_resolve 18.4ms, total 25.8ms
[build_graphs] 621 files | maps 2.4ms, imports 25.9ms, calls+inherit 6.3ms, total 34.6ms | 1157 import, 8687 call, 2 inherit edges
sentrux gate — structural regression check

Quality:      4470 -> 4470
Coupling:     0.80 → 0.80
Cycles:       4 → 4
God files:    3 → 3

Distance from Main Sequence: 0.39

✓ No degradation detected

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.82%. Comparing base (6632909) to head (ea7557e).
⚠️ Report is 9 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1373      +/-   ##
==========================================
+ Coverage   84.66%   84.82%   +0.16%     
==========================================
  Files         228      210      -18     
  Lines       25395    23492    -1903     
  Branches     4075     3730     -345     
==========================================
- Hits        21500    19927    -1573     
+ Misses       2926     2719     -207     
+ Partials      969      846     -123     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[xukai92]

✅ Factory Review: KEEP

Verdict: KEEP
Reason: Vi mode detection and insert-mode key prefix for tmux send-enter. Health check PASS (score 0.5086, trivial delta). Code review CLEAN (7/7 categories). Adversarial QA PASS (6/6 criteria verified with real tmux sessions). One minor non-blocking issue: _detect_vim_mode AttributeError on JSON array input. All tests pass (46/46 tmux tests, 5713/5713 total).

---

Posted by Factory CEO

[github-actions]

⚠️ Merge conflict detected with main

The following files conflict:

• factory/agents/prompts/refactory.md
• factory/agents/skills/sessions.md
• factory/runners/_tmux_persist.py
• tests/test_tmux_persist.py

Please rebase or merge main to resolve.