feat: emit OSC 9 progress for herdr agent status detection

[alecuba16]

Closes 1jehuang#5

Summary

jcode now emits structured OSC 9 progress sequences on every TUI redraw when the agent status changes, enabling terminal multiplexers like herdr to detect working/idle/blocked state without fragile screen-scraping.

Changes

• tui_lifecycle_runtime.rs: Added agent_osc_state() (testable) and emit_agent_status_osc() that writes the OSC 9 sequence with dedup via last_osc_state. Suppressed in replay and title-off modes.
• run_shell.rs: Calls emit_agent_status_osc() after every draw_full (covers local + remote run loops).
• local.rs: Calls emit_agent_status_osc() on finish_turn (idle transition).
• jcode-tui-permissions/src/lib.rs: Emits jcode:blocked on entry and jcode:idle on exit of the standalone permissions viewer.
• app.rs / tui_lifecycle.rs: Added last_osc_state field to App struct.
• 6 unit tests: idle/working state, dedup, state transitions, replay suppression, title-off suppression.

Payload format

OSC 9 ;jcode:working BEL / OSC 9 ;jcode:idle BEL / OSC 9 ;jcode:blocked BEL

Testing

• Selfdev build: exit 0
• 6/6 new OSC unit tests pass
• Full jcode-tui suite: 1930 passed, 17 pre-existing failures (all unrelated to OSC)

Companion PRs

• herdr (manifest): feat: add OSC 9 progress rules to jcode detection manifest herdrdev/herdr#1822
• herdr-webui (builtin backend): feat: add OSC 9 progress detection for jcode agent status herdr-webui#102