rename the TIC system agent to event triage

TIC said nothing about what the agent does, and named the wrong thing: the
tick belongs to the scheduler, which is generic and lives outside it. The
agent's only decision is whether an incoming event deserves an interruption
— it sorts, it never acts — so it is now event-triage, matching the
functional naming of the two memory lints.

- agents/tic/ -> agents/event-triage/, module tic/ -> event_triage/,
  TicManager -> EventTriageManager, TicConfig -> EventTriageConfig
- agent id and chat source: "tic" -> "event-triage"
- config keys: tic.* -> event_triage.*, and the config.yml section tic: ->
  event_triage: (greenfield: previously set values fall back to defaults)
- i18n en/it/fr: Event triage / Triage eventi / Tri des evenements; dropped
  the stale "TIC sessions" mention from the debug-pages description
- docs/system-agents.md, docs/index.md, docs/settings.md, CLAUDE.md, SKALD.md

agents/README.md

@@ -44,7 +44,7 @@ System agents (`type: "system"`) are invisible background agents that maintain t
 
 | Agent | Animal | Role | Elements | Palette |
 |-------|--------|------|----------|---------|
-| **TIC** 👁️ | Spider 🕷️ | Watchful guardian | Sensor nodes, glowing web, radar arcs, notification symbols (bell, letter, calendar) | Dark purple, amber, soft cyan, warm grey |
+| **Event triage** 👁️ | Spider 🕷️ | Watchful guardian | Sensor nodes, glowing web, radar arcs, notification symbols (bell, letter, calendar) | Dark purple, amber, soft cyan, warm grey |
 | **Private Memory Lint** 🧹 | Firefly ✨ | Private memory caretaker | Glowing lantern, memory fragments, tiny notes, sparkles | Warm gold, amber, soft teal, gentle green |
 | **Shared Memory Lint** 🧹 | Bee 🐝 | Shared space caretaker | Scroll with guidelines, honey dipper, honeycomb shapes, tiny documents | Warm amber, gold, soft teal, honey |