refactor: consolidate loading/error states and extract instance actions hook

Frontend:
- Create reusable DataStates components (LoadingState, ErrorState, EmptyState)
- Refactor 12 pages to use shared state components instead of inline JSX
- Extract useInstanceActions hook to eliminate session action duplication
- Update dashboard and sessions pages to use shared hook

OpenSpec:
- Archive completed mobile-app-usability change (44/44 tasks)
- Archive completed add-config-profiles change (15/15 tasks)

Quality: TypeScript check passes, production build succeeds

apps/web/src/pages/config-profiles.tsx

@@ -1,4 +1,5 @@
 import { useCallback, useEffect, useState } from "react";
+import { EmptyState, ErrorState, LoadingState } from "../components/data-states";
 import { Icon } from "../components/icon";
 import { useMobileViewport } from "../hooks/use-mobile-viewport";
 import { extractErrorMessage } from "../utils/errors";
@@ -408,7 +409,7 @@ export const ConfigProfilesPage = () => {
   if (status === "loading") {
     return (
       <div className="container">
-        <p>Loading Config Profiles...</p>
+        <LoadingState message="Loading Config Profiles..." />
       </div>
     );
   }
@@ -416,10 +417,7 @@ export const ConfigProfilesPage = () => {
   if (status === "error") {
     return (
       <div className="container">
-        <p className="text-error">Failed to load Config Profiles.</p>
-        <button onClick={loadData}>
-          <Icon name="refresh" size="sm" /> Retry
-        </button>
+        <ErrorState message="Failed to load Config Profiles." onRetry={loadData} />
       </div>
     );
   }

apps/web/src/pages/dashboard.tsx

@@ -2,15 +2,17 @@ import { useCallback, useEffect, useMemo, useState } from "react";
 import { useNavigate } from "react-router-dom";
 
 import { getDashboardSummary, type DashboardSummary } from "../api/dashboard";
-import { getUserSessions, startInstance, stopInstance, deleteInstance, recreateInstanceTunnel, checkInstanceHealth, type Session as SessionApi, type InstanceHealth } from "../api/sessions";
+import { getUserSessions, checkInstanceHealth, type Session as SessionApi, type InstanceHealth } from "../api/sessions";
 import { listProjects } from "../api/projects";
 import { listRepositories, type GitRepository } from "../api/git_repositories";
 import { listToolTypes, type ToolType } from "../api/tool_types";
 import { updateUserConfig } from "../api/settings";
 import type { Project } from "../types";
+import { EmptyState, ErrorState, LoadingState } from "../components/data-states";
 import { Icon } from "../components/icon";
 import { CreateSessionForm } from "../components/create-session-form";
 import { SessionList } from "../components/session-list";
+import { useInstanceActions } from "../hooks/use-instance-actions";
 
 type HomeStatus = "loading" | "ready" | "error";
 
@@ -31,7 +33,6 @@ export const HomePage = () => {
   const [repositories, setRepositories] = useState<GitRepository[]>([]);
   const [toolTypes, setToolTypes] = useState<ToolType[]>([]);
   const [selectedProject, setSelectedProject] = useState("");
-  const [actionBusy, setActionBusy] = useState<string | null>(null);
   const [tunnelHealth, setTunnelHealth] = useState<Record<string, InstanceHealth>>({});
   const safeSessions = Array.isArray(sessions) ? sessions : [];
 
@@ -58,6 +59,15 @@ export const HomePage = () => {
     void loadHome();
   }, [loadHome]);
 
+  const {
+    loadingSessionId: actionBusy,
+    handleOpen,
+    handleStart,
+    handleStop,
+    handleDelete,
+    handleRecreateTunnel,
+  } = useInstanceActions({ onRefresh: loadHome });
+
   // Poll tunnel health every 30 seconds for running instances
   useEffect(() => {
     const checkHealth = async () => {
@@ -130,64 +140,6 @@ export const HomePage = () => {
     await loadHome();
   };
 
-  const handleOpen = (session: SessionView) => {
-    if (session.url) {
-      window.open(session.url, "_blank", "noopener,noreferrer");
-      return;
-    }
-    if (session.tool_type_interfaces.includes("terminal")) {
-      navigate(`/instances/${session.id}/terminal`);
-      return;
-    }
-    navigate(`/projects/${session.project_id}`);
-  };
-
-  const handleStop = async (session: SessionView) => {
-    if (actionBusy === session.id) return;
-    setActionBusy(session.id);
-    try {
-      await stopInstance(session.project_id, session.repository_id, session.id);
-      await loadHome();
-    } finally {
-      setActionBusy(null);
-    }
-  };
-
-  const handleDelete = async (session: SessionView) => {
-    if (actionBusy === session.id) return;
-    setActionBusy(session.id);
-    try {
-      await deleteInstance(session.project_id, session.repository_id, session.id);
-      setSessions((prev) => prev.filter((s) => s.id !== session.id));
-    } catch {
-      // error - session remains in state
-    } finally {
-      setActionBusy(null);
-    }
-  };
-
-  const handleRecreateTunnel = async (session: SessionView) => {
-    if (actionBusy === session.id) return;
-    setActionBusy(session.id);
-    try {
-      await recreateInstanceTunnel(session.project_id, session.repository_id, session.id);
-      await loadHome();
-    } finally {
-      setActionBusy(null);
-    }
-  };
-
-  const handleStart = async (session: SessionView) => {
-    if (actionBusy === session.id) return;
-    setActionBusy(session.id);
-    try {
-      await startInstance(session.project_id, session.repository_id, session.id);
-      await loadHome();
-    } finally {
-      setActionBusy(null);
-    }
-  };
-
   return (
     <section className="stack home-page">
       <header className="home-hero card">
@@ -202,17 +154,9 @@ export const HomePage = () => {
         </div>
       </header>
 
-      {status === "loading" && <p className="muted">Loading overview...</p>}
+      {status === "loading" && <LoadingState message="Loading overview..." />}
 
-      {status === "error" && (
-        <div className="card stack">
-          <p>Unable to load your workspace overview.</p>
-          <button className="secondary-button" type="button" onClick={() => void loadHome()}>
-            <Icon name="refresh" size="sm" />
-            Retry
-          </button>
-        </div>
-      )}
+      {status === "error" && <ErrorState message="Unable to load your workspace overview." onRetry={() => void loadHome()} />}
 
       {status === "ready" && summary && (
         <>
@@ -260,7 +204,7 @@ export const HomePage = () => {
               <button className="secondary-button" type="button" onClick={() => navigate("/projects")}>View all</button>
             </div>
             {projects.length === 0 ? (
-              <p className="muted">No projects yet.</p>
+              <EmptyState message="No projects yet." />
             ) : (
               <div className="home-project-grid">
                 {projects.map((project) => (

apps/web/src/pages/git-history.tsx

@@ -2,6 +2,7 @@ import { useCallback, useEffect, useState } from "react";
 import { useNavigate, useParams } from "react-router-dom";
 
 import { getCommitDetail, getRepositoryHistory, type CommitDetail, type CommitHistoryEntry, type CommitHistoryResponse } from "../api/git_repositories";
+import { EmptyState, ErrorState, LoadingState } from "../components/data-states";
 import { Icon } from "../components/icon";
 import { useAsyncData } from "../hooks/use-async-data";
 
@@ -54,7 +55,7 @@ export const GitHistoryPage = () => {
   if (status === "loading") {
     return (
       <section className="stack">
-        <p className="muted">Loading commit history...</p>
+        <LoadingState message="Loading commit history..." />
       </section>
     );
   }
@@ -62,11 +63,7 @@ export const GitHistoryPage = () => {
   if (status === "error") {
     return (
       <section className="stack">
-        <p>Failed to load commit history</p>
-        <button className="secondary-button" onClick={() => reload()} type="button">
-          <Icon name="refresh" size="sm" />
-          Retry
-        </button>
+        <ErrorState message="Failed to load commit history" onRetry={reload} />
       </section>
     );
   }

apps/web/src/pages/git-repositories.tsx

@@ -6,6 +6,7 @@ import {
   listRepositories,
 } from "../api/git_repositories";
 import type { GitRepository } from "../api/git_repositories";
+import { EmptyState, ErrorState, LoadingState } from "../components/data-states";
 import { Icon } from "../components/icon";
 import { RepositoryCreateDialog } from "../components/repository-create-dialog";
 import { useAsyncData } from "../hooks/use-async-data";
@@ -48,19 +49,11 @@ export const GitRepositoriesPage = () => {
         </button>
       </div>
 
-      {status === "loading" && <p className="muted">Loading repositories...</p>}
+      {status === "loading" && <LoadingState message="Loading repositories..." />}
 
-      {status === "error" && (
-        <div className="card stack">
-          <p>Failed to load repositories</p>
-          <button className="secondary-button" onClick={() => reload()} type="button">
-            <Icon name="refresh" size="sm" />
-            Retry
-          </button>
-        </div>
-      )}
+      {status === "error" && <ErrorState message="Failed to load repositories" onRetry={reload} />}
 
-      {isEmpty && <p className="muted">No repositories yet. Create your first repository above.</p>}
+      {isEmpty && <EmptyState message="No repositories yet. Create your first repository above." />}
 
       {status === "ready" && safeRepositories.length > 0 && (
         <div className="repository-list">

apps/web/src/pages/profile.tsx

@@ -1,6 +1,7 @@
 import { useCallback, useEffect, useRef, useState } from "react";
 
 import { getProfile, updateProfile, uploadAvatar } from "../api/profile";
+import { EmptyState, ErrorState, LoadingState } from "../components/data-states";
 import { Icon } from "../components/icon";
 import { useAuth } from "../state/auth";
 import { useAsyncData } from "../hooks/use-async-data";
@@ -91,17 +92,9 @@ export const ProfilePage = () => {
     <section className="stack">
       <h1>Profile</h1>
 
-      {displayStatus === "loading" && <p className="muted">Loading profile...</p>}
+      {displayStatus === "loading" && <LoadingState message="Loading profile..." />}
 
-      {displayStatus === "error" && (
-        <div className="card stack">
-          <p>Failed to load profile</p>
-          <button className="secondary-button" onClick={() => reload()} type="button">
-            <Icon name="refresh" size="sm" />
-            Retry
-          </button>
-        </div>
-      )}
+      {displayStatus === "error" && <ErrorState message="Failed to load profile" onRetry={reload} />}
 
       {(displayStatus === "ready" || displayStatus === "saving") && profile && (
         <div className="card stack">

apps/web/src/pages/projects.tsx

@@ -10,6 +10,7 @@ import {
   type ProjectCreateInput,
   type ProjectUpdateInput,
 } from "../api/projects";
+import { EmptyState, ErrorState, LoadingState } from "../components/data-states";
 import { Icon } from "../components/icon";
 import { useAsyncData } from "../hooks/use-async-data";
 import type { Project } from "../types";
@@ -101,19 +102,11 @@ export const ProjectsPage = () => {
         </button>
       </div>
 
-      {status === "loading" && <p className="muted">Loading projects...</p>}
+      {status === "loading" && <LoadingState message="Loading projects..." />}
 
-      {status === "error" && (
-        <div className="card stack">
-          <p>Failed to load projects</p>
-          <button className="secondary-button" onClick={() => reload()} type="button">
-            <Icon name="refresh" size="sm" />
-            Retry
-          </button>
-        </div>
-      )}
+      {status === "error" && <ErrorState message="Failed to load projects" onRetry={reload} />}
 
-      {isEmpty && <p className="muted">No projects yet. Create your first project above.</p>}
+      {isEmpty && <EmptyState message="No projects yet. Create your first project above." />}
 
       {status === "ready" && safeProjects.length > 0 && (
         <div className="project-list">

apps/web/src/pages/repo-workspace.tsx

@@ -1,4 +1,5 @@
 import { useCallback, useEffect, useState } from "react";
+import { EmptyState, ErrorState, LoadingState } from "../components/data-states";
 import { Icon } from "../components/icon";
 import { useMobileViewport } from "../hooks/use-mobile-viewport";
 
@@ -164,26 +165,16 @@ export const RepoWorkspace = () => {
       )}
 
       {status === "loading" && (
-        <p className="muted">Loading repositories...</p>
+        <LoadingState message="Loading repositories..." />
       )}
 
       {status === "error" && (
-        <div className="card stack">
-          <p>Failed to load repositories</p>
-          <button
-            className="secondary-button"
-            onClick={() => void loadRepositories()}
-            type="button"
-          >
-            <Icon name="refresh" size="sm" />
-            Retry
-          </button>
-        </div>
+        <ErrorState message="Failed to load repositories" onRetry={() => void loadRepositories()} />
       )}
 
       {status === "empty" && (
         <div className="card stack">
-          <p>No repositories in this project yet.</p>
+          <EmptyState message="No repositories in this project yet." />
           <Link
             className="primary-button"
             to={`/projects/${projectId}/settings/repositories`}
@@ -486,7 +477,7 @@ const FileBrowser = ({
         </button>
       )}
       {entries.length === 0 && (
-        <p className="muted">No files in this repository yet.</p>
+        <EmptyState message="No files in this repository yet." />
       )}
       {entries.map((entry) => {
         const fileStatus = entry.type === "file" ? getFileStatus(entry.path) : null;

apps/web/src/pages/sessions.tsx

@@ -7,18 +7,15 @@ import { listRepositories, type GitRepository } from "../api/git_repositories";
 import {
   getUserSessions,
   type Session,
-  deleteInstance,
-  stopInstance,
-  startInstance,
   checkInstanceHealth,
-  recreateInstanceTunnel,
 } from "../api/sessions";
 import { listToolTypes, type ToolType } from "../api/tool_types";
 import { getUserConfig, updateUserConfig } from "../api/settings";
-import { Icon } from "../components/icon";
+import { EmptyState, ErrorState, LoadingState } from "../components/data-states";
 import { CreateSessionForm } from "../components/create-session-form";
 import { SessionList } from "../components/session-list";
 import { SessionCard } from "../components/session-card";
+import { useInstanceActions } from "../hooks/use-instance-actions";
 import type { InstanceHealth } from "../api/sessions";
 
 type SessionsStatus = "loading" | "ready" | "error";
@@ -34,11 +31,7 @@ export const SessionsPage = () => {
   const [toolTypes, setToolTypes] = useState<ToolType[]>([]);
   const [selectedProject, setSelectedProject] = useState<string>("");
 
-  const [dirtyDeleteSession, setDirtyDeleteSession] = useState<Session | null>(null);
-  const [dirtyDeleteFiles, setDirtyDeleteFiles] = useState<string[]>([]);
-
   const [tunnelHealth, setTunnelHealth] = useState<Record<string, InstanceHealth>>({});
-  const [loadingSessionId, setLoadingSessionId] = useState<string | null>(null);
 
   const loadSessions = useCallback(async () => {
     setStatus("loading");
@@ -83,7 +76,18 @@ export const SessionsPage = () => {
     void loadToolTypes();
   }, []);
 
-
+  const {
+    loadingSessionId,
+    dirtyDeleteSession,
+    dirtyDeleteFiles,
+    handleOpen,
+    handleStart,
+    handleStop,
+    handleDelete,
+    handleForceDelete,
+    handleRecreateTunnel,
+    clearDirtyDelete,
+  } = useInstanceActions({ onRefresh: loadSessions });
 
   // Poll health every 30 seconds for active web-enabled instances
   useEffect(() => {
@@ -154,116 +158,15 @@ export const SessionsPage = () => {
     await loadSessions();
   };
 
-  const handleStop = async (session: Session) => {
-    if (loadingSessionId === session.id) return;
-    setLoadingSessionId(session.id);
-    try {
-      await stopInstance(session.project_id, session.repository_id, session.id);
-      await loadSessions();
-    } catch {
-      // ignore
-    } finally {
-      setLoadingSessionId(null);
-    }
-  };
-
-  const handleDelete = async (session: Session) => {
-    if (loadingSessionId === session.id) return;
-    setLoadingSessionId(session.id);
-    try {
-      await deleteInstance(session.project_id, session.repository_id, session.id);
-      setDirtyDeleteSession(null);
-      setDirtyDeleteFiles([]);
-      // Remove from local state immediately
-      setSessions((prev) => prev.filter((s) => s.id !== session.id));
-    } catch (error) {
-      const axiosError = error as { response?: { status?: number; data?: { detail?: { changed_files?: string[] } } } };
-      if (axiosError.response?.status === 409) {
-        const detail = axiosError.response.data?.detail;
-        if (detail?.changed_files) {
-          setDirtyDeleteSession(session);
-          setDirtyDeleteFiles(detail.changed_files);
-          return;
-        }
-      }
-    } finally {
-      setLoadingSessionId(null);
-    }
-  };
-
-  const handleForceDelete = async (session: Session) => {
-    if (loadingSessionId === session.id) return;
-    setLoadingSessionId(session.id);
-    try {
-      await deleteInstance(session.project_id, session.repository_id, session.id, true);
-      setDirtyDeleteSession(null);
-      setDirtyDeleteFiles([]);
-      setSessions((prev) => prev.filter((s) => s.id !== session.id));
-    } catch {
-      // ignore
-    } finally {
-      setLoadingSessionId(null);
-    }
-  };
-
-  const handleRecreateTunnel = async (session: Session) => {
-    if (loadingSessionId === session.id) return;
-    setLoadingSessionId(session.id);
-    try {
-      await recreateInstanceTunnel(
-        session.project_id,
-        session.repository_id,
-        session.id
-      );
-      // Refresh sessions to get new URL
-      await loadSessions();
-    } catch {
-      // ignore
-    } finally {
-      setLoadingSessionId(null);
-    }
-  };
-
-  const handleStart = async (session: Session) => {
-    if (loadingSessionId === session.id) return;
-    setLoadingSessionId(session.id);
-    try {
-      await startInstance(session.project_id, session.repository_id, session.id);
-      await loadSessions();
-    } catch {
-      // ignore
-    } finally {
-      setLoadingSessionId(null);
-    }
-  };
-
-  const handleOpen = (session: Session) => {
-    if (session.url) {
-      window.open(session.url, '_blank', 'noopener,noreferrer');
-    } else if (session.tool_type_interfaces?.includes("terminal")) {
-      navigate(`/instances/${session.id}/terminal`);
-    } else {
-      navigate(`/projects/${session.project_id}`);
-    }
-  };
-
   return (
     <section className="stack sessions-page">
       <div className="page-header">
         <h1>Sessions</h1>
       </div>
 
-      {status === "loading" && <p className="muted">Loading sessions...</p>}
+      {status === "loading" && <LoadingState message="Loading sessions..." />}
 
-      {status === "error" && (
-        <div className="card stack">
-          <p>Failed to load sessions</p>
-          <button className="secondary-button" onClick={() => void loadSessions()} type="button">
-            <Icon name="refresh" size="sm" />
-            Retry
-          </button>
-        </div>
-      )}
+      {status === "error" && <ErrorState message="Failed to load sessions" onRetry={() => void loadSessions()} />}
 
       {status === "ready" && (
         <>
@@ -311,7 +214,7 @@ export const SessionsPage = () => {
 
           {/* Dirty Delete Confirmation Modal */}
           {dirtyDeleteSession && (
-            <div className="modal-overlay" onClick={() => setDirtyDeleteSession(null)}>
+            <div className="modal-overlay" onClick={clearDirtyDelete}>
               <div className="modal-content" onClick={(e) => e.stopPropagation()}>
                 <h3>Uncommitted Changes</h3>
                 <p>
@@ -330,7 +233,7 @@ export const SessionsPage = () => {
                 <div className="modal-actions">
                   <button
                     className="secondary-button"
-                    onClick={() => setDirtyDeleteSession(null)}
+                    onClick={clearDirtyDelete}
                     type="button"
                   >
                     Cancel

apps/web/src/pages/settings.tsx

@@ -2,6 +2,7 @@ import { useEffect, useState } from "react";
 import { Link, Outlet, useLocation, useOutletContext } from "react-router-dom";
 
 import { getUserConfig, updateUserConfig, type UserConfig, type UserConfigUpdate } from "../api/settings";
+import { EmptyState, ErrorState, LoadingState } from "../components/data-states";
 import { Icon } from "../components/icon";
 import { useAsyncData } from "../hooks/use-async-data";
 
@@ -71,17 +72,13 @@ export const SettingsPage = () => {
   };
 
   if (status === "loading") {
-    return <section className="stack"><p className="muted">Loading settings...</p></section>;
+    return <section className="stack"><LoadingState message="Loading settings..." /></section>;
   }
 
   if (status === "error") {
     return (
       <section className="stack">
-        <p>Failed to load settings</p>
-        <button className="secondary-button" onClick={() => reload()} type="button">
-          <Icon name="refresh" size="sm" />
-          Retry
-        </button>
+        <ErrorState message="Failed to load settings" onRetry={reload} />
       </section>
     );
   }

apps/web/src/pages/ssh-keys.tsx

@@ -1,6 +1,7 @@
 import { useState } from "react";
 import { useNavigate } from "react-router-dom";
 import { createSSHKey, deleteSSHKey, listSSHKeys, signPayload, verifySignature, type SSHKey } from "../api/ssh_keys";
+import { EmptyState, ErrorState, LoadingState } from "../components/data-states";
 import { Icon } from "../components/icon";
 import { useAsyncData } from "../hooks/use-async-data";
 
@@ -87,7 +88,7 @@ export const SSHKeysPage = () => {
     }
   }
 
-  if (status === "loading") return <div>Loading...</div>;
+  if (status === "loading") return <LoadingState message="Loading SSH keys..." />;
 
   return (
     <section className="stack">
@@ -130,19 +131,11 @@ export const SSHKeysPage = () => {
         </button>
       </form>
 
-      {status === "error" && (
-        <div className="card stack">
-          <p>Failed to load SSH keys</p>
-          <button className="secondary-button" onClick={() => loadKeys()} type="button">
-            <Icon name="refresh" size="sm" />
-            Retry
-          </button>
-        </div>
-      )}
+      {status === "error" && <ErrorState message="Failed to load SSH keys" onRetry={loadKeys} />}
 
       <div className="keys-list">
         {safeKeys.length === 0 ? (
-          <p className="muted">No SSH keys yet. Generate one above.</p>
+          <EmptyState message="No SSH keys yet. Generate one above." />
         ) : (
           safeKeys.map((key) => (
             <div key={key.id} className="key-card">

apps/web/src/pages/tool-workshop.tsx

@@ -1,4 +1,5 @@
 import { useCallback, useEffect, useState } from "react";
+import { EmptyState, ErrorState, LoadingState } from "../components/data-states";
 import { Icon } from "../components/icon";
 import { useMobileViewport } from "../hooks/use-mobile-viewport";
 import { extractErrorMessage } from "../utils/errors";
@@ -491,7 +492,7 @@ export const ToolWorkshopPage = () => {
   if (status === "loading") {
     return (
       <div className="container">
-        <p>Loading Tool Workshop...</p>
+        <LoadingState message="Loading Tool Workshop..." />
       </div>
     );
   }
@@ -499,10 +500,7 @@ export const ToolWorkshopPage = () => {
   if (status === "error") {
     return (
       <div className="container">
-        <p className="text-error">Failed to load Tool Workshop.</p>
-        <button onClick={loadData}>
-          <Icon name="refresh" size="sm" /> Retry
-        </button>
+        <ErrorState message="Failed to load Tool Workshop." onRetry={loadData} />
       </div>
     );
   }
@@ -1305,7 +1303,7 @@ export const ToolWorkshopPage = () => {
 
                 <div className="stack" style={{ gap: "0.5rem" }}>
                   {toolConfigs.length === 0 ? (
-                    <p className="muted">No configurations for this tool type yet.</p>
+                    <EmptyState message="No configurations for this tool type yet." />
                   ) : (
                     toolConfigs.map((config) => (
                       <div