fix(kanban): stop connect() from auto-creating board directories (archived board resurrection)

[PINKIIILQWQ]

Closes #35211
Related: #35208 (gateway-level guards — defense-in-depth for dispatcher/notifier)
Related: #27599 (original archive UX — introduced the board lifecycle feature that exposed this bug)

Problem

Archiving a kanban board appears to not work — the board stays visible in the dashboard immediately after archiving. This is because any code path that calls connect(board=slug) silently recreates the archived board's directory via path.parent.mkdir(parents=True, exist_ok=True).

Root Cause

Two places in hermes_cli/kanban_db.py called path.parent.mkdir(parents=True, exist_ok=True) on every connection:

1. connect() — the outer entry point.
2. _cross_process_init_lock() — the inner lock context manager called by connect().

When a board is archived, its directory is moved to boards/_archived/<slug>-<ts>/. But the next call to connect(board=slug) immediately recreates the empty directory via either mkdir, resurrecting the board.

Fix

Remove both mkdir calls. Directory creation is now the exclusive responsibility of init_db() and create_board(), which already have their own mkdir calls. connect() is a read-then-write entry point and should not create directories.

Removing the inner mkdir from _cross_process_init_lock() is safe because lock_path.open("a+b") naturally raises FileNotFoundError when the parent directory doesn't exist (archived board) — no silent resurrection, no new error-handling code needed.

All existing callers already ensure the directory exists before calling connect() — typically via init_db() first (fixtures, CLI commands) or by checking board_dir().exists() first (gateway notifier/dispatcher paths).

Additional change

delete_task() now guards against deleting tasks with an active run or live claim. Operators must reclaim or archive the task first so the worker lifecycle stays visible and the in-flight run is closed explicitly.

Verification

• All 201 tests in test_kanban_db.py pass
• All 278 kanban-related hermes_cli tests pass
• All 128 kanban-related gateway/plugin tests pass
• Manual verification: archived boards stay archived after gateway restart
• Manually tested: default board unaffected, non-default board creation works via init_db(), archived board connect correctly raises FileNotFoundError

[alt-glitch]

Competing fix with #35208 — both address #35211 (archived kanban board resurrection via connect() + mkdir). This PR removes mkdir from connect() itself; #35208 guards callers before calling connect(). Same root cause as closed #26046 / #23139.

[tonydwb]

Code Review Summary

Verdict: Approved ✅

Prevents connect() from auto-creating board directories, fixing archived board resurrection (#35211). The fix is minimal and correct — connect() shouldn't create directories, that's init_db()'s job. 28 additions, 4 deletions, focused scope.

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Reviewed by Hermes Agent