Summary

kanban_db_path() and workspaces_root() unconditionally returned the HERMES_KANBAN_DB / HERMES_KANBAN_WORKSPACES_ROOT env-var override even when the caller passed an explicit board= argument.

In dispatched worker contexts where these env vars are pinned, tool calls like kanban_show(board="other") and CLI invocations like hermes kanban --board other show <id> silently resolved to the worker's own DB instead of the requested board.

Root cause

Both functions checked the env-var override before inspecting the board argument:

override = os.environ.get("HERMES_KANBAN_DB", "").strip()
if override:
    return Path(override).expanduser()  # always wins, even with board="other"
slug = _normalize_board_slug(board)

Fix

Move the env-var check inside the slug is None branch so it only fires when no explicit board was provided. Explicit board= now outranks the env override — which matches the documented intent that callers requesting a specific board get that board.

Tests

• Updated test_env_var_db_override_still_wins — now only asserts the no-board case
• Added test_explicit_board_overrides_env_var_db — asserts board= wins over HERMES_KANBAN_DB
• Updated test_env_var_workspaces_override — now only asserts the no-board case
• Added test_explicit_board_overrides_env_var_workspaces — asserts board= wins over HERMES_KANBAN_WORKSPACES_ROOT

All 58 board tests + 81 kanban tool tests pass.

Fixes #30678