diff --git a/.pql/pql-plan.json b/.pql/pql-plan.json
index 7666c59a..95e4dfd7 100644
--- a/.pql/pql-plan.json
+++ b/.pql/pql-plan.json
@@ -1,5 +1,5 @@
 {
-  "exported_at": "2026-05-06T09:14:06Z",
+  "exported_at": "2026-05-06T10:04:42Z",
   "decisions": [
     {
       "id": "D-1",
@@ -2040,11 +2040,11 @@
       "type": "task",
       "parent_id": "T-4",
       "title": "implement welcome screen per hi-fi design",
-      "status": "ready",
+      "status": "done",
       "priority": "medium",
       "decision_ref": "D-43",
       "created_at": "2026-04-22 14:08:40",
-      "updated_at": "2026-05-03 20:34:52"
+      "updated_at": "2026-05-06 09:17:22"
     },
     {
       "id": "T-22",
@@ -2673,9 +2673,23 @@
       "priority": "low",
       "created_at": "2026-05-06 08:30:15",
       "updated_at": "2026-05-06 08:30:15"
+    },
+    {
+      "id": "T-83",
+      "type": "task",
+      "title": "design reusable sortable tab system for multitab panes",
+      "status": "in_progress",
+      "priority": "high",
+      "created_at": "2026-05-06 09:17:39",
+      "updated_at": "2026-05-06 09:17:50"
+    }
+  ],
+  "ticket_deps": [
+    {
+      "blocker_id": "T-83",
+      "blocked_id": "T-24"
     }
   ],
-  "ticket_deps": null,
   "ticket_labels": null,
   "history": [
     {
@@ -4005,6 +4019,20 @@
       "old_value": "in_progress",
       "new_value": "done",
       "changed_at": "2026-05-06 07:56:10"
+    },
+    {
+      "ticket_id": "T-21",
+      "field": "status",
+      "old_value": "ready",
+      "new_value": "done",
+      "changed_at": "2026-05-06 09:17:22"
+    },
+    {
+      "ticket_id": "T-83",
+      "field": "status",
+      "old_value": "backlog",
+      "new_value": "in_progress",
+      "changed_at": "2026-05-06 09:17:50"
     }
   ]
 }
diff --git a/docs/design/multitab-pane.md b/docs/design/multitab-pane.md
new file mode 100644
index 00000000..c314ea5d
--- /dev/null
+++ b/docs/design/multitab-pane.md
@@ -0,0 +1,182 @@
+# Multitab pane — design
+
+Ticket: T-83
+Drives: T-24 (secondary Claude pane UI wiring)
+Date: 2026-05-06
+
+## Problem
+
+Some panes need to host multiple, dynamically-spawned views of the
+same kind. The first concrete case is the Claude pane: per
+[D-41](../../decisions/architecture.md#d-41-claude-panes-one-primary-per-repo-tmux-backed),
+each repo has exactly one **primary** Claude pane plus zero or more
+**secondary** panes spawned at runtime. The user needs a way to:
+
+- See which Claude sessions are open
+- Switch between them
+- Spawn a new secondary
+- Close a secondary (primary has no close affordance)
+
+The kernel's existing `TabContribution` system addresses a different
+need — it lets extensions statically declare which widget shows up in
+which **panel slot** (sidebar, workspace, context). It does not
+support dynamic tab instances *within* a single contribution.
+
+This design fills that gap with a reusable widget, so future panes
+that need the same shape (potentially the editor — see D-48 — or
+diff/preview surfaces) can adopt it without reinventing tab strips.
+
+## Non-goals
+
+- Replacing `TabContribution`. Slot-host tabs are static-by-design;
+  this widget is for inside-a-tab dynamism.
+- Window-level tab management (browser-style "tear off into a window").
+- Editor multi-buffer tabs. [D-48](../../decisions/architecture.md#d-48-chrome-budget-no-tabs-no-breadcrumbs-keyboard-first)
+  rejected those; revisiting is a separate decision.
+
+## API sketch
+
+```dart
+class MultitabPane<T> extends StatefulWidget {
+  const MultitabPane({
+    required this.controller,
+    required this.tabBuilder,
+    required this.bodyBuilder,
+    this.onCloseRequested,
+    this.onAddRequested,
+    this.allowReorder = true,
+  });
+
+  final MultitabController<T> controller;
+  final Widget Function(BuildContext, MultitabEntry<T>) tabBuilder;
+  final Widget Function(BuildContext, MultitabEntry<T>) bodyBuilder;
+  final void Function(MultitabEntry<T> entry)? onCloseRequested;
+  final void Function()? onAddRequested;
+  final bool allowReorder;
+}
+
+class MultitabEntry<T> {
+  final String id;          // stable identity (e.g. "claude.primary")
+  final String title;       // display label
+  final bool closeable;     // primary tabs set this false
+  final bool reorderable;   // primary often pinned to position 0
+  final T payload;          // domain object the bodyBuilder renders
+}
+
+class MultitabController<T> extends ChangeNotifier {
+  List<MultitabEntry<T>> get entries;
+  MultitabEntry<T>? get active;
+
+  void add(MultitabEntry<T> entry, {bool activate = true});
+  void remove(String id);
+  void activate(String id);
+  void reorder(String id, int newIndex);
+}
+```
+
+The widget is a thin shell:
+- Renders the tab strip via `ClideTabBar` (or a reorderable variant)
+- Calls `bodyBuilder(active)` for the visible content
+- Routes user gestures to controller methods or callbacks
+- Emits `onCloseRequested` / `onAddRequested` so the host decides
+  the actual lifecycle (e.g. Claude pane spawns a new tmux session,
+  doesn't just append a UI tab)
+
+The host owns the controller and the payload type. The widget never
+touches PTY, IPC, or Claude session naming.
+
+## Rendering
+
+The tab strip lives at the top of the pane chrome. Layout:
+
+```
+┌──────────────────────────────────────────────────────┐
+│ [primary] [secondary 1] [secondary 2] [+]            │
+├──────────────────────────────────────────────────────┤
+│                                                      │
+│             active tab body                          │
+│                                                      │
+└──────────────────────────────────────────────────────┘
+```
+
+- Active tab: filled background, bright text
+- Inactive: muted background, muted text
+- Close glyph (×) appears on hover for `closeable` tabs
+- `+` button at the end if `onAddRequested` is set
+- Drag-to-reorder respects `reorderable`; non-reorderable tabs
+  (primary) are pinned to position 0 and other tabs cannot be
+  dropped before them
+
+## Interaction
+
+- **Click a tab** → activate
+- **Click ×** → call `onCloseRequested(entry)`; host decides whether
+  to confirm, kill the underlying session, etc.
+- **Drag-and-drop** → call `controller.reorder(id, newIndex)` after
+  the gesture completes; controller enforces pinned positions
+- **Click +** → call `onAddRequested()`; host creates the new entry
+  and adds it via `controller.add(...)`
+- **Keyboard**: `⌘1`–`⌘9` jump to tab N; `⌘W` close active (skipped
+  for non-closeable); `⌘⇧[` / `⌘⇧]` cycle prev/next
+
+## Persistence
+
+Out of scope for the widget. Hosts that want to persist tab order or
+which tabs were open across sessions read/write through their own
+settings layer and seed the controller on init.
+
+## Claude pane integration (T-24)
+
+```
+ClaudePane (host)
+└── MultitabPane<ClaudeSessionRef>(
+      controller: claudeTabsController,
+      tabBuilder: (ctx, e) => Text(e.title),
+      bodyBuilder: (ctx, e) => ClaudePaneBody(session: e.payload),
+      onAddRequested: () => kernel.claude.spawnSecondary(),
+      onCloseRequested: (e) => kernel.claude.closeSecondary(e.payload),
+    )
+```
+
+`ClaudeSessionRef` carries the tmux session name + isPrimary. The
+controller is seeded with `[primary]` on boot; secondaries get
+appended as the user clicks `+`. Closing a secondary triggers
+`pane.close` IPC and removes the entry; closing the primary is not
+exposed (`closeable: false`).
+
+## What ships in this ticket
+
+T-83 delivers:
+1. `MultitabPane` widget + `MultitabController` + `MultitabEntry`
+   under `lib/widgets/src/`
+2. Unit tests for controller invariants (pinned positions, active
+   selection survives close, reorder bounds)
+3. Widget tests for the strip (selection, close hover, add button,
+   drag-reorder)
+4. This design doc
+
+T-24 picks up after and wires the Claude pane to it.
+
+## Open questions
+
+- **Q: Where does keyboard handling live?** Host or widget?
+  Recommendation: widget owns `⌘W` / `⌘1`–`⌘9` / cycle; host wires
+  them via the existing kernel commands surface. Avoids each host
+  reinventing the same shortcuts.
+
+  **Nesting caveat:** the widget composes (a Claude tab can host
+  its own `MultitabPane<EditorBuffer>` etc.). Shortcut handling
+  must be scoped to the focus subtree, not registered globally —
+  otherwise the outermost pane consumes `⌘W` even when the user
+  is typing in a nested tab. Implementation: wrap shortcuts in a
+  `Shortcuts` / `Actions` widget inside the pane's `Focus` scope
+  so the innermost focused pane wins via Flutter's normal
+  shortcut-resolution chain.
+
+- **Q: Tab overflow** when many secondaries open? Recommendation:
+  start with horizontal scroll; revisit if it becomes a problem.
+
+- **Q: Tab-strip visual style** — match `ClideTabBar` exactly, or
+  introduce a denser variant for inside-pane use? Recommendation:
+  reuse `ClideTabBar` initially; spin off a `ClideTabBar.dense`
+  variant only if visual hierarchy issues emerge.
diff --git a/docs/diagrams/multitab-pane.d2 b/docs/diagrams/multitab-pane.d2
new file mode 100644
index 00000000..82250f40
--- /dev/null
+++ b/docs/diagrams/multitab-pane.d2
@@ -0,0 +1,166 @@
+title: MultitabPane — architecture {
+  near: top-center
+  shape: text
+  style.font-size: 24
+  style.bold: true
+}
+
+direction: down
+
+host: ClaudePane (host) {
+  shape: rectangle
+  style.fill: "#13161c"
+  style.stroke: "#7c5cff"
+  style.font-color: "#e8ecf2"
+
+  state: ChangeNotifier — owns lifecycle {
+    shape: rectangle
+    style.fill: "#0e1014"
+    style.stroke: "#262a32"
+    style.font-color: "#a0a8b8"
+  }
+}
+
+widget: MultitabPane<T> (widget) {
+  shape: rectangle
+  style.fill: "#13161c"
+  style.stroke: "#262a32"
+  style.font-color: "#e8ecf2"
+
+  shell: builds tabstrip + body shell {
+    shape: rectangle
+    style.fill: "#0e1014"
+    style.stroke: "#262a32"
+    style.font-color: "#a0a8b8"
+  }
+}
+
+controller: MultitabController<T> {
+  shape: rectangle
+  style.fill: "#13161c"
+  style.stroke: "#262a32"
+  style.font-color: "#e8ecf2"
+
+  api: |md
+    add(entry)
+    remove(id)
+    activate(id)
+    reorder(id, idx)
+  | {
+    style.font-color: "#a0a8b8"
+  }
+}
+
+entries: List<MultitabEntry<T>> {
+  shape: rectangle
+  style.fill: "#0e1014"
+  style.stroke: "#262a32"
+  style.font-color: "#a0a8b8"
+
+  primary: primary {
+    shape: rectangle
+    style.fill: "#1a1f28"
+    style.stroke: "#7c5cff"
+    style.font-color: "#e8ecf2"
+    closeable\: false: { shape: text; style.font-color: "#7a8294"; style.font-size: 10 }
+    reorderable\: false: { shape: text; style.font-color: "#7a8294"; style.font-size: 10 }
+  }
+  sec1: secondary 1 {
+    shape: rectangle
+    style.fill: "#13161c"
+    style.stroke: "#262a32"
+    style.font-color: "#a0a8b8"
+  }
+  sec2: secondary 2 {
+    shape: rectangle
+    style.fill: "#13161c"
+    style.stroke: "#262a32"
+    style.font-color: "#a0a8b8"
+  }
+}
+
+ipc: kernel.claude / IPC {
+  shape: rectangle
+  style.fill: "#13161c"
+  style.stroke: "#5a8c5a"
+  style.font-color: "#e8ecf2"
+
+  spawn: spawnSecondary() {
+    shape: rectangle
+    style.fill: "#0e1014"
+    style.stroke: "#262a32"
+    style.font-color: "#a0a8b8"
+  }
+  close: closeSecondary(ref) {
+    shape: rectangle
+    style.fill: "#0e1014"
+    style.stroke: "#262a32"
+    style.font-color: "#a0a8b8"
+  }
+}
+
+host -> controller: owns {
+  style.stroke: "#7a8294"
+  style.font-color: "#7a8294"
+}
+host -> widget: builds with {
+  style.stroke: "#7a8294"
+  style.font-color: "#7a8294"
+}
+controller -> entries: holds {
+  style.stroke: "#7a8294"
+  style.font-color: "#7a8294"
+}
+widget -> controller: subscribes (Listenable) {
+  style.stroke: "#7c5cff"
+  style.font-color: "#a0a8b8"
+}
+
+widget -> host: onAddRequested() {
+  style.stroke: "#d97757"
+  style.font-color: "#d97757"
+}
+widget -> host: onCloseRequested(entry) {
+  style.stroke: "#d97757"
+  style.font-color: "#d97757"
+}
+
+host -> ipc: routes user intent {
+  style.stroke: "#5a8c5a"
+  style.font-color: "#5a8c5a"
+}
+ipc.spawn -> entries.sec2: appends new entry {
+  style.stroke: "#5a8c5a"
+  style.font-color: "#5a8c5a"
+}
+ipc.close -> entries.sec1: removes entry {
+  style.stroke: "#d97757"
+  style.font-color: "#d97757"
+}
+
+note: |md
+  ### Boundary
+
+  **Widget** is generic. It knows
+  about `MultitabEntry<T>` and routes
+  user gestures back to the host. It
+  never touches PTY, IPC, or session
+  naming.
+
+  **Host** owns the controller and
+  decides what `add` / `close` mean
+  in the domain — for Claude that's
+  spawning/killing tmux sessions
+  via IPC.
+
+  This boundary is what makes the
+  widget reusable: any pane that
+  needs N runtime instances can
+  drop it in with their own host
+  and payload type.
+| {
+  shape: rectangle
+  style.fill: "#13161c"
+  style.stroke: "#262a32"
+  style.font-color: "#a0a8b8"
+}
diff --git a/docs/diagrams/multitab-pane.png b/docs/diagrams/multitab-pane.png
new file mode 100644
index 00000000..ca73f871
Binary files /dev/null and b/docs/diagrams/multitab-pane.png differ
diff --git a/docs/wireframes/main/claude-multitab.json b/docs/wireframes/main/claude-multitab.json
new file mode 100644
index 00000000..1cc4b960
--- /dev/null
+++ b/docs/wireframes/main/claude-multitab.json
@@ -0,0 +1,209 @@
+{
+  "name": "Claude Pane — multitab",
+  "shapes": {
+    "canvas": {
+      "type": "Rectangle",
+      "left": 40, "top": 40, "width": 1100, "height": 720,
+      "fillColor": "#0e1014",
+      "strokeColor": "#1c2028"
+    },
+
+    "pane-header": {
+      "type": "Rectangle",
+      "parent": "canvas",
+      "left": 40, "top": 40, "width": 1100, "height": 36,
+      "fillColor": "#13161c",
+      "strokeColor": "#1c2028"
+    },
+    "pane-title": {
+      "type": "Text",
+      "parent": "pane-header",
+      "left": 56, "top": 50,
+      "text": "claude — secondary 2",
+      "fontColor": "#e8ecf2",
+      "fontSize": 12
+    },
+    "pane-subtitle": {
+      "type": "Text",
+      "parent": "pane-header",
+      "left": 56, "top": 64,
+      "text": "tmux · clide-claude-var-mnt-data-projects-clide-2",
+      "fontColor": "#7a8294",
+      "fontSize": 10
+    },
+
+    "tabstrip": {
+      "type": "Rectangle",
+      "parent": "canvas",
+      "left": 40, "top": 76, "width": 1100, "height": 32,
+      "fillColor": "#0e1014",
+      "strokeColor": "#1c2028"
+    },
+
+    "tab-primary": {
+      "type": "Rectangle",
+      "parent": "tabstrip",
+      "left": 56, "top": 80, "width": 132, "height": 28,
+      "fillColor": "#13161c",
+      "strokeColor": "#1c2028",
+      "corners": [4, 4, 0, 0]
+    },
+    "tab-primary-pin": {
+      "type": "Text",
+      "parent": "tab-primary",
+      "left": 64, "top": 86,
+      "text": "📌",
+      "fontColor": "#7a8294",
+      "fontSize": 10
+    },
+    "tab-primary-text": {
+      "type": "Text",
+      "parent": "tab-primary",
+      "left": 84, "top": 86,
+      "text": "primary",
+      "fontColor": "#a0a8b8",
+      "fontSize": 12
+    },
+
+    "tab-sec-1": {
+      "type": "Rectangle",
+      "parent": "tabstrip",
+      "left": 192, "top": 80, "width": 132, "height": 28,
+      "fillColor": "#13161c",
+      "strokeColor": "#1c2028",
+      "corners": [4, 4, 0, 0]
+    },
+    "tab-sec-1-text": {
+      "type": "Text",
+      "parent": "tab-sec-1",
+      "left": 204, "top": 86,
+      "text": "secondary 1",
+      "fontColor": "#a0a8b8",
+      "fontSize": 12
+    },
+    "tab-sec-1-close": {
+      "type": "Text",
+      "parent": "tab-sec-1",
+      "left": 304, "top": 86,
+      "text": "×",
+      "fontColor": "#5a6478",
+      "fontSize": 14
+    },
+
+    "tab-sec-2": {
+      "type": "Rectangle",
+      "parent": "tabstrip",
+      "left": 328, "top": 80, "width": 132, "height": 28,
+      "fillColor": "#1a1f28",
+      "strokeColor": "#7c5cff",
+      "corners": [4, 4, 0, 0]
+    },
+    "tab-sec-2-text": {
+      "type": "Text",
+      "parent": "tab-sec-2",
+      "left": 340, "top": 86,
+      "text": "secondary 2",
+      "fontColor": "#e8ecf2",
+      "fontSize": 12
+    },
+    "tab-sec-2-close": {
+      "type": "Text",
+      "parent": "tab-sec-2",
+      "left": 440, "top": 86,
+      "text": "×",
+      "fontColor": "#a0a8b8",
+      "fontSize": 14
+    },
+
+    "tab-add": {
+      "type": "Rectangle",
+      "parent": "tabstrip",
+      "left": 464, "top": 80, "width": 28, "height": 28,
+      "fillColor": "#0e1014",
+      "strokeColor": "#1c2028",
+      "corners": [4, 4, 0, 0]
+    },
+    "tab-add-glyph": {
+      "type": "Text",
+      "parent": "tab-add",
+      "left": 474, "top": 86,
+      "text": "+",
+      "fontColor": "#7a8294",
+      "fontSize": 14
+    },
+
+    "active-divider": {
+      "type": "Rectangle",
+      "parent": "canvas",
+      "left": 40, "top": 108, "width": 1100, "height": 2,
+      "fillColor": "#7c5cff",
+      "strokeColor": "#7c5cff"
+    },
+
+    "body": {
+      "type": "Rectangle",
+      "parent": "canvas",
+      "left": 40, "top": 110, "width": 1100, "height": 650,
+      "fillColor": "#0e1014",
+      "strokeColor": "#1c2028"
+    },
+    "body-banner-name": {
+      "type": "Text",
+      "parent": "body",
+      "left": 56, "top": 132,
+      "text": "Claude Code  v2.1.128",
+      "fontColor": "#e8ecf2",
+      "fontSize": 12
+    },
+    "body-banner-meta": {
+      "type": "Text",
+      "parent": "body",
+      "left": 56, "top": 148,
+      "text": "Opus 4.7 (1M context)  ·  fresh secondary session",
+      "fontColor": "#7a8294",
+      "fontSize": 11
+    },
+
+    "body-msg-prompt": {
+      "type": "Text",
+      "parent": "body",
+      "left": 56, "top": 200,
+      "text": "› dig into the failing test in test/pty/session_test.dart",
+      "fontColor": "#a0a8b8",
+      "fontSize": 12
+    },
+    "body-msg-resp": {
+      "type": "Text",
+      "parent": "body",
+      "left": 56, "top": 226,
+      "text": "● Looking at the write-keystrokes test. The shell process\n  starts but the echo doesn't appear in the output stream.\n  Let me trace the write path…",
+      "fontColor": "#e8ecf2",
+      "fontSize": 12
+    },
+
+    "prompt-divider": {
+      "type": "Rectangle",
+      "parent": "body",
+      "left": 40, "top": 700, "width": 1100, "height": 1,
+      "fillColor": "#1c2028",
+      "strokeColor": "#1c2028"
+    },
+    "prompt": {
+      "type": "Text",
+      "parent": "body",
+      "left": 56, "top": 712,
+      "text": "›  Try \"run the test in this pane\"",
+      "fontColor": "#5a6478",
+      "fontSize": 12
+    },
+
+    "anno": {
+      "type": "Text",
+      "parent": "canvas",
+      "left": 720, "top": 80,
+      "text": "active tab gets accent border + bottom rule",
+      "fontColor": "#5a6478",
+      "fontSize": 10
+    }
+  }
+}
diff --git a/docs/wireframes/main/claude-multitab.png b/docs/wireframes/main/claude-multitab.png
new file mode 100644
index 00000000..35e43034
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