Agentic Fleet Setup — replace wizard with a skill-guided chat session

Acceptance Criteria

Skill

• packages/extension/skills/fleet/SKILL.md exists with full lifecycle documentation
• Skill covers: create fleet (dev clone mode + release mode), add machine, remove
  machine, dismantle, reconfigure, sync status
• Skill documents the SSH command patterns for each operation (not pseudocode —
  the exact commands the agent should run)
• Skill documents error handling: missing tools (install them), push timeout (retry
  with progress), build failure (read error, fix, retry), service won't start (check
  logs)
• Skill documents the fleet.json schema, service file templates (launchd plist,
  systemd unit), and the tunnel plist template
• Skill documents how to detect local repo paths (walk up from extension path /
  binary path to find .git)
• Skill documents the validation checklist (SSH reachable, tools present, repos
  pushed, build succeeds, service running, tunnel connects)

Extension Changes

• "Create Fleet" button in the panel → opens a new chat session with the fleet
  skill loaded and an initial prompt (e.g. "I want to set up a fleet")
• The fleet_wizard.ts module is removed
• The QuickPick-based commands (createFleet, addMachine, removeMachine, dismantle)
  are removed from extension.ts
• The devBinaryPath, buildServerLaunchdPlist, buildServerSystemdUnit,
  buildTunnelLaunchdPlist, buildRemoteRebuildScript functions move into the skill
  as documented templates (not TypeScript — markdown code blocks the agent copies)
• Panel "Add Machine", "Remove", "Dismantle" actions also launch chat sessions
  with the appropriate fleet skill prompt
• After the agent completes setup, the panel refreshes (the agent tells the user
  to reload, or triggers it programmatically)

Preserved Functionality

• fleet_sync.ts auto-sync on activation — unchanged
• fleet_panel.ts topology/profiles/stats — unchanged (reads fleet.json, shows state)
• fleet_profiles.ts CRUD — unchanged
• fleet_launch.ts session launch — unchanged
• fleet_bridge.ts bridge protocol — unchanged
• fleet_fallback.ts fleet.json read/write — unchanged (the agent uses it via bash)
• fleet_compat.ts version negotiation — unchanged

Key Decisions

Data Contracts

Fleet skill prompt (button → chat):

I want to create a fleet with a remote machine as the server.

Fleet skill operations (the skill documents these as sections):

• /fleet create — full setup flow
• /fleet add <target> — add a machine to existing fleet
• /fleet remove <target> — remove a machine
• /fleet dismantle — tear down the fleet
• /fleet reconfigure — change host/port/SSH alias
• /fleet status — show current state

Constraints & Invariants

• The agent MUST validate SSH connectivity before any remote operation
• The agent MUST NOT store SSH passwords or private keys
• The agent MUST report each step's outcome before proceeding to the next
• The agent MUST offer to install missing tools (not just report them missing)
• Fleet.json writes MUST be atomic (tmp + rename) — the skill documents this
• The canonical server MUST be a system service (launchd/systemd), not a child process
• Sessions MUST survive client disconnect (the skill documents the service config)

Prior Art

• This conversation (2026-08-13) — the manual setup that proved the agentic pattern
• fleet_wizard.ts (being removed) — the sequential implementation this replaces
• pulse-designer score — the existing guided-interview pattern (this is similar but
  uses bash execution instead of form-filling)
• Device Inspector pattern — proven WebviewViewProvider (the panel stays)

Source

Part of #350 (Fleet Panel & Profile UI)
ADR 0005: Managed Fleet
ADR 0007: Fleet Panel and Profile UI