v0.9.0 — todo HUD (OMP-parity live UI) + a2a module

Highlights

todo HUD — OMP-parity live UI

• Above-editor widget rendering the board in OMP's visual language: └─ Tasks · n/m head over nested ├─/└─ checkbox rows
• Progress path: every tree connector turns accent once its phase completes — the completed tree reads as one lit path
• Done rows stay visible (green + strikethrough), current phase mdLink blue, blocked warning + (blocked by …), notes collapse to +n
• Transcript tool-result rows draw the same colored board (LLM-facing text stays the plain board)
• All-done board lingers todo.lingerSecs seconds (default 60; 0 = instant, −1 = never; closed-set row under /config → Tasks → Todo), then auto-clears; any new mutation cancels the timer
• Regression: a real blockedBy edge gates auto-start; completing the blocker auto-starts the dependent

a2a — new module

• A2A Protocol v1.0 bidirectional peer (port of @bacnh85/pi-a2a 0.7.13): 7 outbound tools, 8 commands, opt-in inbound server, local/mDNS/gateway discovery
• Gateway-proxied peers pin to the proxy URL (SSRF-guard fix found against a live switchboard)
• Settings on the central /config panel (Tasks tab); zero new runtime deps (bonjour-service vendored flat)

Full changelog: https://github.com/ceulen-dev/ceulen/blob/main/CHANGELOG.md