feat: convert tmux monitoring into a plugin (B10)

packages/plugin-sdk/ARCHITECTURE.md

@@ -505,14 +505,16 @@ skipped, and it stays in the next snapshot (`isUnregisteredPluginTabType` in
 `src/ui/plugin-host/sdk-ui.ts`. Adding to it is a contract change; removing
 from it is a breaking one. Today it exports: alert, alert-dialog, badge,
 button, card, checkbox, dialog, dropdown-menu, input, label, password-input,
-select, select2, separator, switch, textarea, tooltip, sheet, section-card,
-metric-card, charts, the card grid, `ConnectionScreen` and the connection
-status helpers, `SnippetVariablesDialog`, `FullScreenAppWrapper`, the
-connection log context, `TOTPDialog`, `SSHAuthDialog`, `WarpgateDialog`,
-`PassphraseDialog`, `OPKSSHDialog` (until opkssh moves in Phase C),
-`HostKeyVerificationDialog`, `useTabs`/`useTabsSafe`, `ActionSlot`,
-`ComponentSlot`, `PluginComponent` and `FOLDER_COLORS` (the colour swatches
-folders and workspaces pick from).
+popover, scroll-area, select, select2, separator, skeleton, switch, textarea,
+tooltip, sheet, section-card, metric-card, charts, the card grid,
+`ConnectionScreen` and the connection status helpers,
+`SnippetVariablesDialog`, `FullScreenAppWrapper`, the connection log context,
+`TOTPDialog`, `SSHAuthDialog`, `WarpgateDialog`, `PassphraseDialog`,
+`OPKSSHDialog` (until opkssh moves in Phase C), `HostKeyVerificationDialog`,
+`useTabs`/`useTabsSafe`, `ActionSlot`, `ComponentSlot`, `PluginComponent` and
+`FOLDER_COLORS` (the colour swatches folders and workspaces pick from).
+**B10** added `popover`, `scroll-area` and `skeleton` for the tmux-monitor
+plugin's session tree and its new-session/kill popovers.
 
 **B9** added what a terminal-like surface needs from the shell: `cn`,
 `useConfirmation`, `useIsMobile`, `runAdaptivePolling`; the terminal look
@@ -1186,6 +1188,9 @@ connect pipeline instead of importing ssh2 helpers from core:
   since the file-manager plugin's interactive connect route and its dedicated
   transfer sessions both need their own keepalive/timeout defaults rather than
   falling back to the generic `"plugin"` purpose.
+- **B10** added `"tmux"` to `PluginSshPurpose` the same way (core's
+  `SshConnectPurpose` already had it), for the tmux-monitor plugin's pooled
+  connection and the `tmux.sessions` service it provides to the terminal.
 - **B9** added what an interactive transport needs, for the terminal:
   `resolveHost(hostId, { syncId? })` (the host with secrets, by sync id first,
   audited), the `"terminal"` purpose, `interactive` and `hostKeySocket` on

packages/plugin-sdk/FINISH-LIST.md

@@ -163,14 +163,6 @@ build`'s esbuild step has no static-asset-copy pipeline the way core's Vite
   `optionalAuth`, because share-link and room guests authenticate inside the
   handler with their token. Guest auth itself is unchanged; review it with the
   rest of the public routes.
-- **B9 (ssh-terminal):** tmux has no provider yet. The terminal calls the
-  optional `tmux.sessions` v1 (`detect`, `attachOrCreate`, `waitForSession`)
-  and skips tmux attach without it (auto-tmux, the tmux monitor's attach, the
-  session picker). The toolbar's old host action list only ever held the
-  Tmux Monitor button, which is gone with it. `TmuxSessionPicker` lives in
-  ssh-terminal now. Owner: B10, which provides the service (the helpers are
-  `hosts/tmux/helper.ts`) and contributes its toolbar button to
-  `terminal.toolbar`.
 - **B9 (ssh-terminal):** recording has no provider yet. The terminal calls the
   optional `recordings.writer` v1 `open(meta)` and gets a sink with
   `append(chunk)` (one call per 300 ms batch, the first starting with the
@@ -225,6 +217,36 @@ build`'s esbuild step has no static-asset-copy pipeline the way core's Vite
   fails on `src/ui/lib/host-to-ssh-host.ts` spelling `web-endpoint` (the
   `pluginSettings` lookup B8 added). Not allowlisted and not introduced here.
   Owner: D0 (read it through a registry or allowlist it with a reason).
+- **B10 (tmux-monitor):** `enable_tmux_monitor` is still a live `ssh_data`
+  column; only the copy-into-plugin-settings migration shipped
+  (`tmux-monitor-settings-migration.ts`), the same as B6/B7's own columns.
+  Every core read site (`host.ts`, `host-normalizers.ts`,
+  `host-bulk-routes.ts`, `database.ts`'s encrypt/decrypt round trip) still
+  reads the column directly. Dropping it in lockstep (`schema.ts`,
+  `db/index.ts`, a drizzle migration per dialect, `schema:generate`) is the
+  same follow-up the B6/B7/B8 lines above describe. Owner: a dedicated
+  follow-up step, or D0.
+- **B10 (tmux-monitor):** `terminalToolbar.openTmuxMonitor` and
+  `terminalToolbar.tmuxDetach` are dead locale keys (nothing calls
+  `t("terminalToolbar.openTmuxMonitor")` or `t("terminalToolbar.tmuxDetach")`
+  anywhere in the tree; the terminal's own live detach button uses
+  `terminalToolbar.detachTmux`/`detachTmuxDescription` instead). Pre-existing,
+  not introduced by this step; sibling dead keys
+  (`copyTerminalUrlAction`/`copyDockerUrlAction`/`copyHostMetricsUrlAction`,
+  `terminalUrlCopied`/`dockerUrlCopied`/`hostMetricsUrlCopied`) are the same
+  vintage, from before the generic `hosts.copiedToClipboard`/
+  `copyViewUrlAction` replaced them. Owner: whoever next cleans up
+  `src/ui/locales/en.json`, or D0.
+- **B10 (tmux-monitor):** no plugin contributes an "Open Tmux Monitor" (or
+  "Open Docker" / "Open Tunnel" / "Open Host Metrics") quick link into
+  `terminal.toolbar` today; that whole quick-link row was dropped when the
+  toolbar was rebuilt as a generic action slot (`ai` is the only real
+  `terminal.toolbar` contributor, for its assistant button) and never
+  replaced per-feature. Adding tmux-monitor's own link is straightforward
+  (`app.registerSlotContribution("terminal.toolbar", ...)` plus
+  `app.registerAction` opening the singleton tab) but is a shared gap across
+  four plugins, not specific to this step. Owner: D1, or whoever revisits the
+  toolbar's quick-link row.
 
 ## Manual checks after 2.9.0
 

packages/plugin-sdk/src/backend.ts

@@ -612,7 +612,8 @@ export type PluginSshPurpose =
   | "tunnel"
   | "file-manager"
   | "file-transfer"
-  | "terminal";
+  | "terminal"
+  | "tmux";
 
 export type PluginSshAuthOutcome =
   | { status: "ready" }