feat: convert file manager into a plugin

packages/plugin-sdk/ARCHITECTURE.md

@@ -1067,9 +1067,15 @@ connect pipeline instead of importing ssh2 helpers from core:
   a chain has no single resolved host of its own.
 - `prepare(host, { client, purpose })`, `openTransport`,
   `classifyKeyboardInteractive` and `autoResponses` are the lower level for a
-  transport with its own prompt flow (docker's console, host metrics).
+  transport with its own prompt flow (docker's console, host metrics, **B6**'s
+  interactive file-manager connect with its TOTP/Warpgate parking flow).
 - `requiresSecret(authType)` and `supportsBackground(authType)` ask the
   provider.
+- **B6** added `"file-manager"` and `"file-transfer"` to `PluginSshPurpose`
+  (core's `SshConnectPurpose` already had them; the SDK type had lagged),
+  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.
 
 Each new connection is audited and runs as the current actor; pooled reuse is
 not. Connections and pool entries are closed on deactivate.
@@ -1608,8 +1614,8 @@ What the lint fence enforces today, in `eslint.config.mjs`:
 | Core importing a plugin backend                  | **Error** | 0         | -          |
 | A plugin backend importing frontend code or `@/` | **Error** | 0         | -          |
 | The shell importing plugin code                  | **Error** | 0         | -          |
-| A plugin frontend importing core through `@/`    | Warning   | 108 files | D1         |
-| A plugin importing core by relative path         | Warning   | 67 files  | D1         |
+| A plugin frontend importing core through `@/`    | Warning   | 138 files | D1         |
+| A plugin importing core by relative path         | Warning   | 68 files  | D1         |
 | A plugin importing another plugin's source       | Warning   | 3 files   | B18        |
 
 A warning does not fail a build, so the counts are held by
@@ -1639,11 +1645,17 @@ Known specifics:
   an `optionalDependency` (added in A2; it previously declared nothing, and
   the loader had no reason to order the two).
 - Core feature servers that are not plugins yet still own ports: tunnel 30003,
-  file-manager 30004, dashboard 30006, tmux 30010, serial 30011 and homepage 30012. Each keeps its nginx block until its own Phase B step. No plugin owns
-  a port any more (A4).
+  dashboard 30006, tmux 30010, serial 30011 and homepage 30012. Each keeps its
+  nginx block until its own Phase B step. No plugin owns a port any more (A4).
+  **B6** moved file-manager off port 30004 onto `/plugin-api/file-manager/`.
 - The terminal component and `TerminalTabContent` stay in core until the
-  terminal's Phase B step (session manager, split view and file-manager
-  callbacks). ssh-terminal registers them through the legacy alias.
+  terminal's Phase B step (session manager, split view). ssh-terminal
+  registers them through the legacy alias; **B6** switched every core caller
+  of the file manager over to `invokeAction("files.openHost"/"files.openEditor")`
+  instead of the `openFileManager`/`openFileInEditor` shell callbacks it
+  removed, so `TerminalWindow.tsx`'s embedding of the core terminal component
+  is now the only file-manager-adjacent legacy-core import left, tracked the
+  same way as any other plugin depending on an unconverted core component.
 - Host data columns (`enableDocker`, `enableRdp`, `guacamoleConfig` and so on)
   stay in core types until Phase B moves them. Only UI branches on them left
   the shell.

packages/plugin-sdk/FINISH-LIST.md

@@ -23,14 +23,16 @@ it's done.
   is the SDK copy fleets now uses; core's copy was left in place rather than
   turned into a re-export, since host-metrics's own conversion step is where
   its imports should move wholesale. Owner: host-metrics's Phase B step.
-- **B5 (proxmox):** `useConnectionRetry`, `runAdaptivePolling` and `cn` are
-  duplicated in `plugins/proxmox/src/frontend/stats/` rather than shared with
-  core's `src/ui/lib/` originals, matching the same "add to the SDK once a
-  second plugin needs it" call B3 made for `ManagerCardShell`. host-metrics's
-  own conversion needs the same two hooks for its stats tab, so promote both
-  into `@termix/plugin-sdk/frontend` (and `cn` into `@termix/plugin-sdk/ui`)
-  the next time either is touched. Owner: D1, or host-metrics's Phase B step
-  if it lands first.
+- **B5 (proxmox):** `runAdaptivePolling` and `cn` are duplicated in
+  `plugins/proxmox/src/frontend/stats/` rather than shared with core's
+  `src/ui/lib/` originals. `useConnectionRetry` (the third duplicate B5 left
+  here) is resolved: **B6** promoted it into `@termix/plugin-sdk/frontend`
+  once file-manager became its fourth caller (after proxmox, docker,
+  host-metrics, remote-desktop) and switched proxmox's own copy over too.
+  host-metrics's own conversion needs `runAdaptivePolling` for its stats tab,
+  so promote it into `@termix/plugin-sdk/frontend` (and `cn` into
+  `@termix/plugin-sdk/ui`) the next time either is touched. Owner: D1, or
+  host-metrics's Phase B step if it lands first.
 - **B5 (proxmox):** `runDueProxmoxAutoSyncs` in
   `plugins/proxmox/src/backend/routes.ts` still reaches
   `createCurrentPluginSettingsRepository`/`createCurrentHostRepository` by
@@ -40,3 +42,41 @@ it's done.
   bulk read today. A `ctx.settings.listHostsWithKey` or similar SDK addition
   would close this, if a second plugin's background scan ever needs the same
   shape. Owner: D1.
+- **B6 (file-manager):** `plugins/file-manager/src/frontend/components/PdfPreview.tsx`
+  runs pdfjs without a worker (main-thread parsing) because `termix-plugin
+build`'s esbuild step has no static-asset-copy pipeline the way core's Vite
+  build resolves a `?url` import to a hashed `/assets/` file. Fine for the
+  small files this preview usually opens; restoring a real worker needs the
+  CLI (`packages/plugin-sdk/cli/commands/build.mjs`) to gain a way to emit an
+  extra file into `dist/` and have the frontend reference it by its served
+  `/plugin-assets/<id>/` path. Owner: D1, or whichever step first needs a
+  worker or other static asset from a plugin bundle.
+- **B6 (file-manager):** `transfer-tuning.ts`'s adaptive-tuning profile still
+  persists to a JSON file under `DATA_DIR` rather than `ctx.kv`, and
+  `HostFilesTab.tsx`'s `t()` calls plus the manifest's `contributes.settings.host`
+  `labelKey`s deliberately point at two different key paths (`hosts.*` and
+  `settings.host.*`) for the same three fields, both carrying the same English
+  text - a minor duplication from keeping the host editor's exact existing
+  section verbatim (`registerHostEditorSection`) instead of switching it to
+  the schema-driven settings form. Neither blocks anything; flagging for
+  whoever next touches this plugin's settings UI.
+- **B6 (file-manager):** `TabContext.tsx`'s `computeUniqueTitle` compares
+  `tabType === "file_manager"` (an activity-log type string, not a tab type -
+  the real tab type has always been `"files"`), so that branch has never
+  matched and silently falls through to the terminal title. Pre-existing,
+  unrelated to the conversion; noted rather than fixed per the lean-mode
+  rules. Owner: whoever next touches tab title logic.
+- **B6 (file-manager):** `enable_file_manager`, `default_path` and
+  `scp_legacy` are still live `ssh_data` columns; only the copy-into-plugin-
+  settings migration shipped (`file-manager-settings-migration.ts`). Every
+  core read site the earlier exploration found (`host.ts`,
+  `host-normalizers.ts`, `host-bulk-routes.ts`, `credentials.ts`,
+  `host-internal-routes.ts`, `database.ts`'s encrypt/decrypt round trip,
+  `plugins/host-view.ts`, `ctx-hosts.ts`, plus the frontend's
+  `HostEditorData.ts`/`HostManagerData.ts`/`SidebarTree.tsx`/quick-connect
+  mapping) still reads the column directly rather than
+  `ctx.settings.getHost`. Switching every one of those and then dropping the
+  column in lockstep (`schema.ts`, `db/index.ts`, a drizzle migration per
+  dialect, `schema:generate`) is real, separate work this step didn't
+  attempt, since none of those reads block the plugin conversion itself.
+  Owner: a dedicated follow-up step, or D0.

packages/plugin-sdk/src/backend.ts

@@ -577,7 +577,9 @@ export type PluginSshPurpose =
   | "proxmox"
   | "fleet"
   | "remote-desktop"
-  | "tunnel";
+  | "tunnel"
+  | "file-manager"
+  | "file-transfer";
 
 export type PluginSshAuthOutcome =
   | { status: "ready" }

packages/plugin-sdk/src/frontend.ts

@@ -13,6 +13,7 @@
  * and every plugin bundle.
  */
 
+import { useCallback, useEffect, useRef, useState } from "react";
 import type { ComponentType, ReactNode, Ref } from "react";
 import type { PluginManifest } from "./manifest.js";
 
@@ -75,8 +76,6 @@ export interface ShellApi {
   openSingletonTab: (type: string, options?: OpenTabOptions) => void;
   closeTab: (tabId: string) => void;
   renameTab: (tabId: string, label: string) => void;
-  openFileInEditor: (host: PluginHostRecord, path: string) => void;
-  openFileManager: (host: PluginHostRecord, path?: string) => void;
   openTerminalTab: (host: PluginHostRecord, path?: string) => void;
   /** Opens a rail view in the left sidebar. */
   openRailView: (id: string) => void;
@@ -733,5 +732,205 @@ export function invokeAction(id: string, ...args: unknown[]): Promise<unknown> {
   return requireHost().invokeAction(id, ...args);
 }
 
+// ---------------------------------------------------------------------------
+// Connection retry
+// ---------------------------------------------------------------------------
+
+export type ConnectionRetryStatus =
+  "connecting" | "connected" | "error" | "disconnected";
+
+export interface UseConnectionRetryOptions {
+  connect: () => void | Promise<void>;
+  maxAttempts?: number;
+  baseDelayMs?: number;
+  maxDelayMs?: number;
+  enabled?: boolean;
+  autoStart?: boolean;
+}
+
+export interface UseConnectionRetryResult {
+  status: ConnectionRetryStatus;
+  attempt: number;
+  maxAttempts: number;
+  nextRetryInMs: number | null;
+  markConnected: () => void;
+  markFailed: () => void;
+  retryNow: () => void;
+  reset: () => void;
+}
+
+const COUNTDOWN_TICK_MS = 250;
+const RETRY_JITTER_RATIO = 0.1;
+
+export function computeReconnectDelay(
+  attempt: number,
+  baseDelayMs: number,
+  maxDelayMs: number,
+  random = Math.random,
+): number {
+  const base = Math.min(
+    baseDelayMs * Math.pow(2, Math.max(0, attempt - 1)),
+    maxDelayMs,
+  );
+  const jitter = base * RETRY_JITTER_RATIO * (random() * 2 - 1);
+  return Math.max(baseDelayMs, Math.min(maxDelayMs, Math.round(base + jitter)));
+}
+
+/**
+ * Exponential-backoff reconnect with jitter, for a plugin's own connect flow
+ * (docker's console, host-metrics polling, remote desktop tokens, the file
+ * manager). Promoted here once a fourth plugin needed its own copy of the
+ * same hook.
+ */
+export function useConnectionRetry({
+  connect,
+  maxAttempts = 8,
+  baseDelayMs = 2000,
+  maxDelayMs = 8000,
+  enabled = true,
+  autoStart = true,
+}: UseConnectionRetryOptions): UseConnectionRetryResult {
+  const [status, setStatus] = useState<ConnectionRetryStatus>("connecting");
+  const [attempt, setAttempt] = useState(0);
+  const [nextRetryInMs, setNextRetryInMs] = useState<number | null>(null);
+
+  const connectRef = useRef(connect);
+  connectRef.current = connect;
+
+  const enabledRef = useRef(enabled);
+  enabledRef.current = enabled;
+
+  const attemptRef = useRef(0);
+  const retryTimeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+  const countdownIntervalRef = useRef<ReturnType<typeof setInterval> | null>(
+    null,
+  );
+  const isMountedRef = useRef(true);
+  const markFailedRef = useRef<() => void>(() => {});
+
+  const clearTimers = useCallback(() => {
+    if (retryTimeoutRef.current) {
+      clearTimeout(retryTimeoutRef.current);
+      retryTimeoutRef.current = null;
+    }
+    if (countdownIntervalRef.current) {
+      clearInterval(countdownIntervalRef.current);
+      countdownIntervalRef.current = null;
+    }
+  }, []);
+
+  const runConnect = useCallback(() => {
+    if (!isMountedRef.current) return;
+    setStatus("connecting");
+    try {
+      void Promise.resolve(connectRef.current()).catch(() => {
+        markFailedRef.current();
+      });
+    } catch {
+      markFailedRef.current();
+    }
+  }, []);
+
+  const scheduleRetry = useCallback(() => {
+    if (attemptRef.current >= maxAttempts) {
+      setStatus("disconnected");
+      setNextRetryInMs(null);
+      return;
+    }
+
+    attemptRef.current += 1;
+    setAttempt(attemptRef.current);
+
+    const delay = computeReconnectDelay(
+      attemptRef.current,
+      baseDelayMs,
+      maxDelayMs,
+    );
+
+    let remaining = delay;
+    setNextRetryInMs(remaining);
+    countdownIntervalRef.current = setInterval(() => {
+      remaining = Math.max(0, remaining - COUNTDOWN_TICK_MS);
+      setNextRetryInMs(remaining);
+    }, COUNTDOWN_TICK_MS);
+
+    retryTimeoutRef.current = setTimeout(() => {
+      clearTimers();
+      if (!isMountedRef.current || !enabledRef.current) return;
+      runConnect();
+    }, delay);
+  }, [baseDelayMs, maxDelayMs, maxAttempts, clearTimers, runConnect]);
+
+  const markConnected = useCallback(() => {
+    clearTimers();
+    attemptRef.current = 0;
+    setAttempt(0);
+    setNextRetryInMs(null);
+    if (isMountedRef.current) setStatus("connected");
+  }, [clearTimers]);
+
+  const markFailed = useCallback(() => {
+    clearTimers();
+    if (!isMountedRef.current) return;
+    setStatus("error");
+    if (enabledRef.current) {
+      scheduleRetry();
+    } else {
+      setNextRetryInMs(null);
+    }
+  }, [clearTimers, scheduleRetry]);
+  markFailedRef.current = markFailed;
+
+  const retryNow = useCallback(() => {
+    clearTimers();
+    attemptRef.current = 0;
+    setAttempt(0);
+    setNextRetryInMs(null);
+    runConnect();
+  }, [clearTimers, runConnect]);
+
+  const reset = useCallback(() => {
+    clearTimers();
+    attemptRef.current = 0;
+    setAttempt(0);
+    setNextRetryInMs(null);
+    if (isMountedRef.current) setStatus("connecting");
+  }, [clearTimers]);
+
+  useEffect(() => {
+    isMountedRef.current = true;
+    if (autoStart) {
+      runConnect();
+    }
+    return () => {
+      isMountedRef.current = false;
+      clearTimers();
+    };
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  useEffect(() => {
+    if (enabled && status === "error" && !retryTimeoutRef.current) {
+      scheduleRetry();
+    }
+    if (!enabled) {
+      clearTimers();
+      setNextRetryInMs(null);
+    }
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [enabled]);
+
+  return {
+    status,
+    attempt,
+    maxAttempts,
+    nextRetryInMs,
+    markConnected,
+    markFailed,
+    retryNow,
+    reset,
+  };
+}
+
 export type { PluginManifest } from "./manifest.js";
 export type { ReactNode };