fix(terminal): ignore stale env.cwd from a different session's cd

[ethernet8023]

What does this PR do?

The terminal environment is shared process-globally (collapsed to the "default" key), so env.cwd tracks the LAST session that ran a command. _resolve_command_cwd() trusted env.cwd unconditionally — no ownership check — so when session A's cd left env.cwd pointing at A's checkout, session B's first terminal command inherited A's stale cwd and ran in the wrong workspace.

The file tools already solved this exact shared-env problem with _live_cwd_if_owned() checking env.cwd_owner (tools/file_tools.py:272). The terminal tool never got the same guard.

Fix: capture env.cwd_owner BEFORE the current session claims it, and pass it as prev_owner to _resolve_command_cwd. When the previous owner was a different session, env.cwd is stale — fall through to default_cwd (the config/override cwd for this session) instead. Once the session has claimed the env, subsequent calls in the same session still trust env.cwd so in-session cd state survives.

Related Issue

Fixes new sessions in the desktop app frequently being in the wrong pwd :D

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)

Changes Made

• tools/terminal_tool.py — _resolve_command_cwd(): added prev_owner param; when the env's previous owner was a different session, env.cwd is stale and falls through to default_cwd
• tools/terminal_tool.py — call site (line ~2373): capture prev_cwd_owner = getattr(env, "cwd_owner", "") before claiming the env
• tools/terminal_tool.py — both _resolve_command_cwd call sites (background + foreground): pass prev_owner=prev_cwd_owner
• tests/tools/test_terminal_task_cwd.py — two new regression tests

How to Test

1. scripts/run_tests.sh tests/tools/test_terminal_task_cwd.py -v — 12 tests pass (10 existing + 2 new)
2. scripts/run_tests.sh tests/tools/test_terminal_tool.py tests/tools/test_terminal_task_cwd.py tests/tools/test_terminal_config_env_sync.py tests/tools/test_terminal_compound_background.py tests/tools/test_terminal_exit_semantics.py -v — 114 tests pass, no regressions
3. scripts/run_tests.sh tests/tools/test_file_tools.py -v — 52 tests pass (file_tools share the cwd_owner concept)

New tests:

• test_stale_env_cwd_from_different_session_is_ignored — env owned by session-A, session-B calls terminal → command runs with config cwd, not session-A's stale env.cwd
• test_same_session_env_cwd_is_trusted_after_first_claim — env owned by same session → env.cwd is trusted (in-session cd survives)

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: Linux (NixOS)

Documentation & Housekeeping

• N/A — no config keys, no architecture changes, no tool schema changes