agent: repoint roles to frank-medium/dankclaw-3090; sync niri tweaks, memories, managed skills

- config.yml: default/commit -> frank-medium (dankserver); task/tiny/smol/vision -> frank-small (dankclaw-3090); vision xhigh
- models.yml: add llamacpp (dankclaw-3090) provider; frank-large preserve_thinking + context notes
- niri: focus-ring/border/shadow layout, hot-corners off, re-add noctalia.kdl include; blankpad eDP-1 scale 1.0
- memories: flush rollouts; retire frank_large + marreta_authentik skills; add auth-chain/kv-pool/quadlet-log skills
- managed-skills: 40+ new fleet runbook skills
- agent/skills: import built-in skill set

agent/skills/handoff/SKILL.md

@@ -0,0 +1,16 @@
+---
+name: handoff
+description: Compact the current conversation into a handoff document for another agent to pick up.
+argument-hint: "What will the next session be used for?"
+disable-model-invocation: true
+---
+
+Write a handoff document summarising the current conversation so a fresh agent can continue the work. Save to the temporary directory of the user's OS - not the current workspace.
+
+Include a "suggested skills" section in the document, naming which skills the next agent should call the Skill tool for.
+
+Do not duplicate content already captured in other artifacts (specs, plans, ADRs, issues, commits, diffs). Reference them by path or URL instead.
+
+Redact any sensitive information, such as API keys, passwords, or personally identifiable information.
+
+If the user passed arguments, treat them as a description of what the next session will focus on and tailor the doc accordingly.