fix(kanban): clear _INITIALIZED_PATHS in remove_board so recycled DBs re-init schema

Archiving or deleting a board via remove_board() leaves the path's
"schema already initialized" entry in the module-level cache. A
concurrent connect(board=<slug>) call (e.g. the dashboard event-stream
poll loop) then:

  1. resolves the same kanban.db path,
  2. recreates the directory + an empty sqlite file because
     connect() does mkdir(parents=True, exist_ok=True),
  3. skips the CREATE TABLE pass because the cache entry says the
     schema is already in place,
  4. errors on the next read with `no such table: task_events`.

Drop the cache entry before mutating the filesystem so the fresh file
gets a proper schema init on next connect(). Applies to both
archive=True (rename) and archive=False (rmtree) branches.

Fixes #23833.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

hermes_cli/kanban_db.py

@@ -534,6 +534,11 @@ def remove_board(slug: str, *, archive: bool = True) -> dict:
     if get_current_board() == normed:
         clear_current_board()
 
+    # A concurrent connect(board=normed) after the rename/delete recreates
+    # an empty sqlite file via mkdir(exist_ok=True); the cache entry must be
+    # dropped first so the schema init pass re-runs on that fresh file.
+    _INITIALIZED_PATHS.discard(str((d / "kanban.db").resolve()))
+
     if archive:
         archive_root = boards_root() / "_archived"
         archive_root.mkdir(parents=True, exist_ok=True)