What does this PR do?

Carries an in-flight /goal across every session_id rebind so the goal judge loop doesn't silently die after compression. The goal row is keyed by goal:<session_id> in SessionDB.state_meta; when _compress_context() mints a child session_id on the agent, every site that syncs a stored session_id to the agent's new id must also migrate that row, otherwise /goal status reports "No active goal" with no warning.

The reporter localised one site exactly (cli.py:7567-7572, manual /compress). Code review surfaced four more sites with the same rebind pattern that all need the same treatment:

This PR adds migrate_goal(old_sid, new_sid) in hermes_cli/goals.py and wires it at all five sites. Migration semantics:

• Active and paused goals carry over (with turns_used, last_verdict, paused_reason intact).
• Terminal goals (done, cleared) stay with the original session — they belong to the session that completed them.
• The old key is marked cleared via the existing clear_goal() helper so /goal status under the dead session reflects reality.
• No-ops on empty/identical session ids.

Gateway sites wrap the call in a defensive try/except since gateway logging deliberately swallows non-fatal errors.

Related Issue

Fixes #18467

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 🔒 Security fix
• 📝 Documentation update
• ✅ Tests (adding or improving test coverage)
• ♻️ Refactor (no behavior change)
• 🎯 New skill (bundled or hub)

Changes Made

• hermes_cli/goals.py — add migrate_goal(old_session_id, new_session_id)
• cli.py — wire migrate_goal at the manual /compress, auto-compression, and single-query rebind sites
• gateway/run.py — wire migrate_goal at the post-run sync and session-split sites (with try/except for non-fatal failure)
• tests/hermes_cli/test_goals.py — add TestMigrateGoal (7 unit cases: active carry, status preservation, old-cleared, done/cleared not migrated, paused state, no-goal noop, empty-sid noop)
• tests/cli/test_manual_compress.py — add test_manual_compress_migrates_active_goal_to_child_session integration test that plants a goal, runs _manual_compress end-to-end, and asserts migration

How to Test

1. python -m pytest tests/hermes_cli/test_goals.py tests/cli/test_manual_compress.py -q — 38/38 pass
2. Manual: hermes → /goal port the thing → a few turns → /compress → /goal status should show the goal still active under the new session id (previously: "No active goal")

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: macOS 15.2

Documentation & Housekeeping

• I've updated relevant documentation (README, docs/, docstrings) — or N/A
• I've updated cli-config.yaml.example if I added/changed config keys — or N/A
• I've updated CONTRIBUTING.md or AGENTS.md if I changed architecture or workflows — or N/A
• I've considered cross-platform impact (Windows, macOS) per the compatibility guide — or N/A
• I've updated tool descriptions/schemas if I changed tool behavior — or N/A

Screenshots / Logs

$ python -m pytest tests/hermes_cli/test_goals.py tests/cli/test_manual_compress.py -q
38/38 pass