Fleet UI Phase 3: Fleet command center + inject

[Wirasm]

Phase 3: Fleet Command Center + Inject

Part of #562 (Fleet UI Epic)

PRD: .claude/PRPs/prds/fleet-ui-honryu-visibility.prd.md — Phase 3

What

Evolve the Dashboard into a fleet command table when fleet mode is active, and add an inject command bar for sending tasks to workers from the UI.

Why

Phases 1-2 give visibility scattered across existing views. Phase 3 consolidates into a dedicated fleet command center with communication capability.

Scope

3.1 Dashboard → Fleet Table

• When state.is_fleet_active(), render a fleet command table instead of card grid:
  • Columns: Branch, Status, Task, Ack, Report, Agent
  • Brain row visually distinct (ice left border, "(brain)" suffix)
  • Sorting: brain first, then by status (waiting > working > idle > stopped)
  • Each row clickable → navigates to Detail view
  • When fleet NOT active → existing card grid (backward compat)

3.2 Extract inject logic to kild-core

• Move write_to_inbox() from crates/kild/src/commands/inject.rs to crates/kild-core/src/sessions/fleet.rs
• New function: write_inbox_message(team, branch, text) -> Result<()>
• CLI delegates to new kild-core function

3.3 Inject Command Bar

• Persistent text input + "Send" button at bottom of Fleet view
• Contextual: selected row determines target worker
• On submit: calls write_task() + write_inbox_message() (claude) or write_stdin() (other agents)
• Add inject_input and inject_target to MainView state

Files

• crates/kild-core/src/sessions/fleet.rs — add write_inbox_message()
• crates/kild/src/commands/inject.rs — delegate to kild-core
• crates/kild-ui/src/views/dashboard_view.rs — fleet table + inject bar
• crates/kild-ui/src/views/main_view/main_view_def.rs — inject input state
• crates/kild-ui/src/actions.rs — inject_message() action

Depends on

• Fleet UI Phase 1: Agent status visibility #563 (Phase 1: FleetStore)
• Fleet UI Phase 2: Dropbox / task visibility #564 (Phase 2: Dropbox state)