Add TUI fleet dashboard pane (Phase C1)

CHANGELOG.md

@@ -7,6 +7,14 @@ loosely while pre-1.0 (breaking changes can land on minor bumps).
 
 ## [Unreleased]
 
+- **Fleet dashboard pane (Phase C1).** The TUI consumes fleet SSE (`stream_id` +
+  `depth`) into an in-memory tree and paints a right-rail dashboard: depth
+  indent, agent, active tool, token totals, and a `◇` marker on reconcile JIT
+  workers. `Ctrl-w f` / click focuses the conversation pane bound to that
+  stream; Esc on a running row uses the existing in-flight cancel. Reconcile
+  `mode=ensure` waves show residual vs held plus the current wave in the same
+  pane. See [Fleet](docs/tui/fleet.md).
+
 ## [0.13.10] — 2026-09-21
 
 ### Fixed

CMakeLists.txt

@@ -353,9 +353,11 @@ target_sources(arbiter PRIVATE
     src/tui/sidebar.cpp
     src/tui/sidebar_format.cpp
     src/tui/history_sidebar.cpp
+    src/tui/fleet.cpp
     src/tui/menu.cpp
     src/tui/opentui/sidebar_frame.cpp
     src/tui/opentui/history_sidebar_frame.cpp
+    src/tui/opentui/fleet_frame.cpp
     src/tui/opentui/menu_frame.cpp
     src/tui/opentui/pane_frame.cpp
 )
@@ -921,6 +923,26 @@ if(INDEX_BUILD_TESTS)
     )
     add_test(NAME unit_sidebar COMMAND unit_sidebar)
 
+    # Fleet tree state machine: SSE/event → rows, JIT teardown, tokens.
+    add_executable(unit_fleet
+        tests/test_fleet.cpp
+        src/tui/fleet.cpp
+        src/tui/sidebar_format.cpp
+        src/model_catalog.cpp
+        src/model_context.cpp
+        src/styled_text.cpp
+        src/theme.cpp
+        src/tui/tui_design.cpp
+        src/json.cpp
+    )
+    target_include_directories(unit_fleet PRIVATE
+        ${CMAKE_SOURCE_DIR}/include
+        ${CMAKE_SOURCE_DIR}/third_party/doctest
+    )
+    target_compile_definitions(unit_fleet PRIVATE
+        ARBITER_THEMES_DIR="${CMAKE_SOURCE_DIR}/themes")
+    add_test(NAME unit_fleet COMMAND unit_fleet)
+
     add_executable(unit_todo_resolve
         tests/test_todo_resolve.cpp
         src/todo_resolve.cpp
@@ -1848,7 +1870,6 @@ if(INDEX_BUILD_TESTS)
     )
     add_test(NAME unit_remote_connect COMMAND unit_remote_connect)
 
-<<<<<<< HEAD
     # JSON number grammar (incomplete frac/exp). Separate from #342's
     # unit_json (surrogate pairs in parse_string) so the two PRs do not
     # share tests/test_json.cpp or the CMake insert after unit_logger.
@@ -1861,7 +1882,7 @@ if(INDEX_BUILD_TESTS)
         ${CMAKE_SOURCE_DIR}/third_party/doctest
     )
     add_test(NAME unit_json_numbers COMMAND unit_json_numbers)
-=======
+
     # Unary --connect DELETE/PATCH body cap.  Separate binary so
     # unit_remote_connect stays network-free; this one stands up a
     # loopback server against RemoteApiClient's one-shot curl handles.
@@ -1882,7 +1903,6 @@ if(INDEX_BUILD_TESTS)
         Threads::Threads
     )
     add_test(NAME unit_remote_http COMMAND unit_remote_http)
->>>>>>> origin/main
 
     # tui_design.cpp includes themes_data.h — wire every unit target that
     # compiles it to the embed generator (same header as the main binary).
@@ -1902,6 +1922,7 @@ if(INDEX_BUILD_TESTS)
         unit_conversation_titling
         unit_message_replay_roundtrip
         unit_remote_connect
+        unit_fleet
     )
         arbiter_use_embedded_themes(${_t})
     endforeach()

ROADMAP.md

@@ -59,16 +59,16 @@ calendar commitments.
 ### Phase 5 — Multi-agent mission control
 - [x] **Intent engine foundations-** Hybrid classify/route before dispatch (heuristic, then advisor-model LLM); seed slots for plans/todos; fail-open into index; `POST /v1/intent` + SSE `intent` event
 - [x] **Intent reconcile (Phase A)-** `POST /v1/reconcile`: compile `target_state` + invariants into a state contract, observe a bound workspace, require verification, optional snapshot rollback; `@arbiter/sdk` `IntentClient`; durable `reconcile_runs` + SSE
-- [x] **JIT ΔS waves (Phase B / #208)-** `mode=ensure` wave loop: resolve `agent_map` / clause.agent / capability fallback, spawn ephemeral clones for active ΔS only, re-observe as success proof, teardown before the next wave; budgets `max_waves` / `max_wall_ms` / `max_agents_per_wave` / `max_retries_per_clause`; SSE `agent.spawned` / `agent.teardown`. Observe mode and `/v1/orchestrate` unchanged. Fleet UI remains Phase C
+- [x] **JIT ΔS waves (Phase B / #208)-** `mode=ensure` wave loop: resolve `agent_map` / clause.agent / capability fallback, spawn ephemeral clones for active ΔS only, re-observe as success proof, teardown before the next wave; budgets `max_waves` / `max_wall_ms` / `max_agents_per_wave` / `max_retries_per_clause`; SSE `agent.spawned` / `agent.teardown`. Observe mode and `/v1/orchestrate` unchanged
 - [x] **Always-on presence-** Constitution `presence.mode: always_on`; a pair colleague looks over a peer's shoulder after each tool batch and may inject `[PRESENCE: …]` context. Fail-open; cannot halt. SSE `presence` + TUI `◎ presence`. Opposite lifetime of JIT (#208).
-- [ ] **Fleet dashboard pane-** Live tree of depth, agent, tools, tokens; click-to-focus/Ctrl-W bindings
+- [x] **Fleet dashboard pane-** Live tree of depth, agent, tools, tokens; click-to-focus / `Ctrl-w f` ([docs](docs/tui/fleet.md))
 - [ ] **Plan to execution observability-** Planner plans as first-class objects with progress against todos
 - [ ] **Delegation policies-** Consitutions declare max depth, allowed callees, budget caps (tokens/$)
 - [ ] ~~**Workflow recipes-** Checked-in “crews” (JSON): ordered/parallel graphs of agents + shared todo board~~
 - [ ] **Advisor policy packs-** Reusable gate profiles (strict / coding / research)
 
 **Acceptance criteria:** 
-- [ ] A user can watch and steer a 5-agent job.
+- [x] A user can watch and steer a 5-agent job.
 
 ### Phase 6 — 1.0
 - [ ] **Security defaults pass-** Safer TUI exec prompts; clearer sandbox docs; threat model refresh in SECURITY.md

docs/concepts/fleet-streaming.md

@@ -70,4 +70,5 @@ The master orchestrator's provider deltas stream live (same as sub-agents). Inco
 ## See also
 
 - [SSE event catalog](sse-events.md)
+- [TUI fleet dashboard](../tui/fleet.md)
 - [`POST /v1/orchestrate`](../api/orchestrate.md)

docs/concepts/sse-events.md

@@ -61,6 +61,7 @@ Spec-compatible A2A clients hit [`POST /v1/a2a/agents/:id`](../api/a2a/dispatch.
 
 - [A2A protocol](a2a.md) — the Agent2Agent counterpart to this catalog.
 - [Fleet streaming](fleet-streaming.md)
+- [TUI fleet dashboard](../tui/fleet.md)
 - [Advisor](advisor.md) — gate signal grammar, modes, redirect budget.
 - [Presence](presence.md) — always-on peer review and mid-turn injection.
 - [Intent](intent.md) — pre-dispatch classify/route.

docs/tui/commands.md

@@ -42,6 +42,7 @@ Each pane is an independent conversation view. See [panes.md](panes.md) for the
 | `Ctrl-w c`                 | Close the focused pane. The pane's exec thread is joined cleanly; in-flight turn is cancelled. |
 | `Ctrl-w t`                 | Toggle the conversation-history sidebar (left rail).                    |
 | `Ctrl-w b`                 | Enter the sidebar to pick a prior conversation or start a new one.    |
+| `Ctrl-w f`                 | Show the fleet dashboard (live multi-agent tree) and enter it.        |
 
 ## Background loops
 

docs/tui/fleet.md

@@ -0,0 +1,74 @@
+# Fleet dashboard
+
+The fleet pane is a live tree of every agent turn in the current job — master, `/agent` / `/parallel` children, and reconcile JIT workers. It consumes the existing [fleet streaming](../concepts/fleet-streaming.md) SSE model (`stream_id` + `depth`); it is not a second orchestrator.
+
+Presence (`◎ presence`) is the opposite lifetime: residents stay in the room. Fleet rows are request-scoped and go away when the job ends (JIT clones disappear on `agent.teardown`).
+
+## When it appears
+
+The pane occupies the **right rail** (~24–28 columns) once a job has at least one stream, the same width breakpoint as the session sidebar (96 remaining columns). Unlike the session sidebar, it **stays up in multi-pane layouts** — that is when you need it.
+
+Idle sessions keep the rail free so conversation panes are not crowded. An empty Fleet box is not shown unless you force focus with `Ctrl-w f`.
+
+When both Fleet and Session want the rail (single pane, wide terminal, a job is live), Fleet stacks on top and Session sits below.
+
+## What each row shows
+
+```
+╭ Fleet ──────────────╮
+│ ensure · wave 2     │
+│ Δ 3 residual · 2 held│
+│                     │
+│ ● index        fetch│
+│ ├ ● researcher_a 1.2k│
+│ └ ◇ writer          │
+╰─────────────────────╯
+```
+
+- **Indent** follows `depth` (0 master, 1 delegated, 2 sub-sub). The depth cap is 2; the tree does not invent a third level.
+- **Status:** `●` running, `✓` ok, `✗` failed, `○` opened but not yet started.
+- **Name** of the agent. Reconcile JIT workers get a `◇` marker (ephemeral clone).
+- **Active tool** while a `/cmd` is in flight; otherwise **token totals** for that stream.
+
+The overlay at the top is reconcile-only: `mode=ensure` residual vs held clause counts and the current wave, next to spawn/teardown rows. The pane does not run reconcile (that is still `POST /v1/reconcile`); it only displays events.
+
+## Steer / focus
+
+Selecting a row focuses the conversation pane bound to that stream so you can watch its output. Bindings follow the existing pane / sidebar conventions:
+
+| Input | Effect |
+|-------|--------|
+| `Ctrl-w f` | Show the fleet pane and enter it (second press hides). |
+| Click a fleet row | Select that agent and focus its pane. |
+| `↑` / `↓` (or `k` / `j`) | Move the selection (while fleet is focused). |
+| `Enter` | Focus / open the pane bound to the selected stream. |
+| `Esc` | On a **running** row: cancel that pane's in-flight turn (existing kill-switch). Otherwise leave fleet focus. |
+| Wheel over the tree | Scroll the list. |
+
+`/parallel` children stream into the **host** pane (interim `→ agent` headers). Selecting them focuses that host — the dashboard does not auto-split a pane per child (that would drown the layout). `/pane` spawns already have their own leaf; selecting that agent focuses the spawned pane.
+
+Cancel does **not** invent a per-stream kill protocol. Esc maps to the same `cancel_pane_turn` path as interrupting a focused conversation pane (local `CancelToken` or remote `POST /v1/requests/:id/cancel`).
+
+## Event → tree
+
+| Event | Tree |
+|-------|------|
+| `stream_start` | Open a row (`stream_id`, `depth`, agent). |
+| `agent.spawned` | Open a JIT row (`clone_id`, `◇`). |
+| `agent_start` / `text` | Mark running. |
+| `tool_call` | Set / clear the active tool. |
+| `token_usage` | Add input + output on that stream. |
+| `reconcile.delta` | Overlay: residual, held, wave. |
+| `stream_end` | Mark ended; keep the row until the next job. |
+| `agent.teardown` | Remove the JIT row immediately. |
+| `done` / new `request_id` | End leftovers / clear the previous job. |
+
+See [SSE events](../concepts/sse-events.md) and [Fleet streaming](../concepts/fleet-streaming.md).
+
+## See also
+
+- [Panes](panes.md) — split / focus / `/pane`
+- [Keybindings](keybindings.md)
+- [Streaming](streaming.md)
+- [Presence](../concepts/presence.md) — always-on residents
+- [Reconcile](../concepts/reconcile.md) — JIT ΔS waves

docs/tui/index.md

@@ -6,7 +6,7 @@ Rendering uses [OpenTUI](https://github.com/anomalyco/opentui) (native cell-buff
 
 A pane is to a conversation what a tab is to a browser. A new pane is a new conversation against an agent of your choosing; multiple panes run side-by-side or stacked, each independently typing, streaming, and waiting for its agent. Background loops (long-running agent processes) live alongside; foreground panes can spawn child panes (`/pane <agent> <msg>`) whose results land back in the spawner when done.
 
-Start with `arbiter`. The default layout is a single pane covering the main terminal area. A **left-hand conversation sidebar** lists prior threads and lets you start a new one (`Ctrl-w b` to enter, `Ctrl-w t` to toggle visibility). A **right-hand sidebar** shows session usage, agent/model, todos, and recent tool activity when the terminal is wide enough (MCP appears only after MCP tools are used); `Ctrl-w s` toggles it. `Ctrl-w v` / `Ctrl-w h` split the main area.
+Start with `arbiter`. The default layout is a single pane covering the main terminal area. A **left-hand conversation sidebar** lists prior threads and lets you start a new one (`Ctrl-w b` to enter, `Ctrl-w t` to toggle visibility). A **right-hand sidebar** shows session usage, agent/model, todos, and recent tool activity when the terminal is wide enough (MCP appears only after MCP tools are used); `Ctrl-w s` toggles it. A **fleet dashboard** (`Ctrl-w f`) occupies that same right rail while a multi-agent job is running — live tree of depth, agent, tool, and tokens; it stays visible with several conversation panes. `Ctrl-w v` / `Ctrl-w h` split the main area.
 
 ## Screen anatomy
 
@@ -55,6 +55,7 @@ Token totals also appear in the pane header stats row (right side of row 1) when
 - **[Slash commands](commands.md)** — the full `/cmd` catalogue, grouped by category.
 - **[Keybindings](keybindings.md)** — every key, chord, and modifier the editor recognizes.
 - **[Panes](panes.md)** — multi-pane layouts: split, focus, close, `/pane` spawn semantics.
+- **[Fleet](fleet.md)** — live multi-agent tree: depth, tools, tokens, click-to-focus.
 - **[Streaming](streaming.md)** — what you see during a turn: thinking spinner, tool-call indicator, verbose mode, cancellation.
 - **[Sessions](sessions.md)** — global conversations, autosave / mid-turn checkpoints, compaction.
 - **[Output UX](output-ux.md)** — tool timeline, thinking rows, permission cards, replay chrome.

docs/tui/keybindings.md

@@ -12,6 +12,7 @@ Arbiter ships its own line editor. Bindings below are the complete set the edito
 | Wheel | Scroll pane / history list under the pointer |
 | Drag split gutter | Resize adjacent panes |
 | Left-click history row | Switch to that conversation |
+| Left-click fleet row | Focus the pane bound to that stream |
 | Right sidebar | Ignored (display-only) |
 
 Disable with `"mouse": false` under `layout` in `~/.arbiter/tui.json`.
@@ -85,9 +86,21 @@ cards. See [output-ux.md](output-ux.md).
 | `^W c`       | Close the focused pane. Its exec thread is joined; in-flight turn is cancelled. Last remaining pane cannot be closed. |
 | `^W t`       | Toggle the conversation-history sidebar (left rail). Preference is saved to `~/.arbiter/tui.json`. |
 | `^W b`       | Enter the conversation sidebar for selection. Auto-shows the sidebar if hidden. Use `↑`/`↓` and `Enter`; `Esc` cancels. |
+| `^W f`       | Show the fleet dashboard and enter it. Second press hides it. Click a row or `Enter` to focus that stream's pane; `Esc` on a running row cancels that pane's turn. |
 
 If the chord byte doesn't match any of the above, it's silently dropped — the editor returns to the normal input state. `^W` followed by a regular character does *not* fall through to insertion; the chord window always consumes its byte.
 
+## Fleet dashboard (when focused via `^W f` or a click)
+
+| Key       | Action |
+|-----------|--------|
+| `↑` / `↓` | Move selection (`j` / `k` aliases). |
+| `Enter`   | Focus the conversation pane bound to that stream. |
+| `Esc`     | Cancel the selected in-flight turn if it is running; otherwise leave fleet focus. |
+| `PgUp` / `PgDn` | Page the tree. |
+
+See [Fleet](fleet.md).
+
 ## Conversation sidebar (when focused via `^W b`)
 
 | Key       | Action                                                                       |

docs/tui/panes.md

@@ -103,6 +103,7 @@ When `layout.mouse` is enabled in `~/.arbiter/tui.json` (the default), the TUI e
 | Wheel over scrollback | Scroll that pane (does not steal keyboard focus) |
 | Left-click a conversation in the history sidebar | Select and switch to it |
 | Drag a split gutter | Resize the two adjacent panes asymmetrically |
+| Left-click a fleet row | Focus the conversation pane bound to that stream |
 | Right sidebar | Display-only — clicks and wheel over it are ignored |
 
 Set `"layout": { "mouse": false }` to keep keyboard-only input (useful inside tmux without `set -g mouse on`, or when the host terminal fights with mouse capture). Text selection copy uses OSC 52; under tmux enable `set -g set-clipboard on` (or an equivalent clipboard passthrough).

docs/tui/streaming.md

@@ -26,7 +26,7 @@ This indicator runs in the output pump and updates at ~80 ms cadence. It clears
 
 Model deltas land in the scroll region as they arrive via `StreamRenderer`: `BlockParser` suppresses `/cmd` lines (unless `/verbose`) and forwards unambiguous incomplete prose immediately, `MarkdownRenderer` commits styled spans on newline and exposes a replaceable **live tail** for the in-progress line so tokens paint word-by-word, non-diff fenced code streams into `CodeSegment` (draw-time collapse — first eight body lines plus a live `… +N lines` summary, no placeholder artifacts in scrollback), and ` ```diff ` patches become `DiffSegment` panels (full-width for file adds/deletes; split for edits) with a `Patch #N` action line. Streamed patches **pause the model stream** on an interactive review card (↑↓/Enter, or `[a]`/`[r]`/`[A]`/Esc; PgUp/PgDn scrolls). Use [`/diff`](commands.md) for manual review of remaining pending patches, `/accept-edits` to keep auto-applying, or `/diff apply` to write immediately under the conversation workspace directory (creates missing files; exact hunk-header match; `/diff undo` restores when unchanged). Styling resolves from `tui.json`'s `content` tokens through `StyleId` → OpenTUI highlights — no ANSI round-trip on the master stream path. User echoes, advisor/loop/presence banners, and interrupt markers use the same prose path. Always-on `CONTEXT` notes paint as `◎ presence · <watcher>`; `SILENT` reviews stay quiet. Vertical rhythm (`block_gap` / `panel_gap` / `prose_paragraph_gap`) and panel surfaces (`code_bg`, `diff_bg_*`) are theme tokens — see [themes.md](themes.md).
 
-Sub-agent progress uses the same pipeline with `kInterim` policy: dimmed prose, collapsed fences, capped at eight display rows / 480 columns. The master's synthesis turn carries the full result.
+Sub-agent progress uses the same pipeline with `kInterim` policy: dimmed prose, collapsed fences, capped at eight display rows / 480 columns. The master's synthesis turn carries the full result. The [fleet dashboard](fleet.md) (`Ctrl-w f`) is the live tree of those streams — depth, agent, active tool, tokens — so you do not have to read raw SSE.
 
 ### 3. Tool calls