fix(desktop): deliver cron results to source session

[Th0rgal]

What does this PR do?

Routes unattended cron results back to the durable Desktop/WebUI conversation that created the job instead of falling through to the configured messaging home channel. Desktop now captures its stored session key as the local delivery origin while keeping the ephemeral UI window id separate. Local delivery follows compression continuations, rejects cross-surface session ids, merges observed cron messages into live gateway history, and polls the selected stored transcript so the open Desktop window sees the result.

This preserves and credits Enhe’s two commits from #60923, then generalizes the WebUI session-store delivery path to Desktop.

Related issues

• Relates to Cron WebUI runs can show prompt-only sessions and unknown platform 'webui' delivery errors #45360
• Relates to When opening the Hermes TUI (desktop app), the agent cannot proactively speak #52073
• Builds on fix(cron): deliver WebUI targets via session store #60923

Type of change

• Bug fix
• Tests

Validation

• pytest tests/cron/test_scheduler.py -q — 237 passed
• pytest tests/test_tui_gateway_server.py -q — 384 passed
• Desktop TypeScript typecheck
• Desktop background-sync Vitest — 3 passed
• ruff check on changed Python files
• git diff --check

Tested on macOS arm64.

[teknium1]

Thanks for preserving the focused SessionDB delivery approach from #60923. The underlying Desktop/WebUI cron-origin problem still exists on current main: tools/cronjob_tools.py:285-308 requires platform/chat context that tui_gateway/server.py:2825-2830 does not bind for local sessions, and cron/scheduler.py:1132-1138 / 1537-1575 still routes such origins through gateway Platform(...) dispatch.

Problems

• tui_gateway/server.py:2325 sets session_id=session_key unconditionally. Current main intentionally prefers agent.session_id in tui_gateway/server.py:2807-2829 and re-anchors the durable key after compression in tui_gateway/server.py:4367-4445. Preserve that newer identity handling when adding the local delivery origin.

Suggested changes

• Salvage the local-session routing and observed-message delivery, but layer Desktop/WebUI platform/chat fields onto current _set_session_context without replacing its session-id selection.
• Adapt the Desktop hydration work to current sessions.changed synchronization (tui_gateway/server.py:3060-3123) rather than restoring the older polling-only assumptions.

Automated hermes-sweeper review.

[teknium1]

Current main deliberately prefers agent.session_id here when present (tui_gateway/server.py:2807-2829) and later re-anchors session_key after compression. Please retain that identity derivation while adding the Desktop/WebUI origin fields; unconditionally using session_key would regress the current compression-safe path.