feat: mobile repo workspace with tabbed navigation

- Add mobile viewport detection to RepoWorkspace
- Implement bottom tab navigation (Files, Editor, Git, Terminal)
- Add repository and branch selectors for mobile
- Create mobile workspace layout with tab bar
- Add CSS styles for mobile workspace components
- Desktop layout remains unchanged

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

@@ -1,5 +1,6 @@
 import { useCallback, useEffect, useState } from "react";
 import { Icon } from "../components/icon";
+import { useMobileViewport } from "../hooks/use-mobile-viewport";
 
 import { Link, useParams, useSearchParams } from "react-router-dom";
 
@@ -18,6 +19,8 @@ import { WorkspaceHeader } from "../components/workspace-header";
 import { listToolTypes } from "../api/tool_types";
 import type { ToolType } from "../api/tool_types";
 
+type MobileTab = "files" | "editor" | "git" | "terminal";
+
 type WorkspaceStatus = "loading" | "ready" | "error" | "empty";
 
 interface FileTreeEntry {
@@ -43,6 +46,8 @@ interface Project {
 export const RepoWorkspace = () => {
   const { projectId } = useParams<{ projectId: string }>();
   const [searchParams, setSearchParams] = useSearchParams();
+  const isMobile = useMobileViewport();
+  const [mobileTab, setMobileTab] = useState<MobileTab>("files");
 
   const [status, setStatus] = useState<WorkspaceStatus>("loading");
   const [project, setProject] = useState<Project | null>(null);
@@ -190,67 +195,70 @@ export const RepoWorkspace = () => {
 
       {status === "ready" && repositories.length > 0 && (
         <>
-          {selectedRepoId && (
-            <GitToolbar
-              projectId={projectId!}
-              repoId={selectedRepoId}
-              currentBranch={currentBranch}
-              branches={branches}
-              hasRemote={Boolean(selectedRepo?.remote_url)}
-              isMirror={Boolean(selectedRepo?.is_mirror)}
-              onBranchChange={(branch) => {
-                setCurrentBranch(branch);
-                const newParams = new URLSearchParams(searchParams);
-                newParams.set("branch", branch);
-                setSearchParams(newParams);
-              }}
-              onRefresh={() => {
-                void loadBranches();
-                void loadGitStatus();
-                window.dispatchEvent(new CustomEvent("refresh-file-tree"));
-              }}
-            />
-          )}
-          <div className="workspace-layout">
-            <aside className="workspace-sidebar">
-              <div className="sidebar-section">
-                <label className="form-field">
-                  Repository
+          {isMobile ? (
+            // Mobile Layout
+            <div className="mobile-workspace">
+              <div className="mobile-workspace-header">
+                <select
+                  value={selectedRepoId || ""}
+                  onChange={(e) => handleRepoChange(e.target.value)}
+                  className="mobile-repo-selector"
+                >
+                  {repositories.map((repo) => (
+                    <option key={repo.id} value={repo.id}>
+                      {repo.name}
+                    </option>
+                  ))}
+                </select>
+                {selectedRepoId && (
                   <select
-                    value={selectedRepoId || ""}
-                    onChange={(e) => handleRepoChange(e.target.value)}
+                    value={currentBranch}
+                    onChange={(e) => {
+                      const branch = e.target.value;
+                      setCurrentBranch(branch);
+                      const newParams = new URLSearchParams(searchParams);
+                      newParams.set("branch", branch);
+                      setSearchParams(newParams);
+                    }}
+                    className="mobile-branch-selector"
                   >
-                    {repositories.map((repo) => (
-                      <option key={repo.id} value={repo.id}>
-                        {repo.name}
+                    {branches.map((branch) => (
+                      <option key={branch} value={branch}>
+                        {branch}
                       </option>
                     ))}
                   </select>
-                </label>
+                )}
               </div>
 
-              {selectedRepoId && (
-                <>
+              <div className="mobile-workspace-content">
+                {mobileTab === "files" && selectedRepoId && (
                   <FileBrowser
                     projectId={projectId!}
                     repoId={selectedRepoId}
                     gitStatus={gitStatus}
                   />
-                {gitStatus && (
-                  <CommitPanel
-                    projectId={projectId!}
-                    repoId={selectedRepoId}
-                    modified={gitStatus.modified}
-                    added={gitStatus.added}
-                    deleted={gitStatus.deleted}
-                    untracked={gitStatus.untracked}
-                    onCommit={() => {
-                      void loadGitStatus();
-                      window.dispatchEvent(new CustomEvent("refresh-file-tree"));
-                    }}
-                  />
                 )}
-                {selectedRepoId && (
+                {mobileTab === "editor" && selectedRepoId && (
+                  <FileEditor projectId={projectId!} repoId={selectedRepoId} />
+                )}
+                {mobileTab === "git" && selectedRepoId && gitStatus && (
+                  <div className="mobile-git-view">
+                    <CommitPanel
+                      projectId={projectId!}
+                      repoId={selectedRepoId}
+                      modified={gitStatus.modified}
+                      added={gitStatus.added}
+                      deleted={gitStatus.deleted}
+                      untracked={gitStatus.untracked}
+                      onCommit={() => {
+                        void loadGitStatus();
+                        window.dispatchEvent(new CustomEvent("refresh-file-tree"));
+                      }}
+                    />
+                  </div>
+                )}
+                {mobileTab === "terminal" && selectedRepoId && (
                   <InstanceList
                     projectId={projectId!}
                     repoId={selectedRepoId}
@@ -259,17 +267,126 @@ export const RepoWorkspace = () => {
                     toolTypes={toolTypes}
                   />
                 )}
-              </>
-            )}
-          </aside>
+              </div>
 
-          <main className="workspace-main">
-            {selectedRepoId && (
-              <FileEditor projectId={projectId!} repoId={selectedRepoId} />
-            )}
-          </main>
-        </div>
-      </>
+              <div className="mobile-workspace-tabs">
+                <button
+                  className={`mobile-workspace-tab ${mobileTab === "files" ? "active" : ""}`}
+                  onClick={() => setMobileTab("files")}
+                  type="button"
+                >
+                  <Icon name="folder" size="sm" />
+                  <span>Files</span>
+                </button>
+                <button
+                  className={`mobile-workspace-tab ${mobileTab === "editor" ? "active" : ""}`}
+                  onClick={() => setMobileTab("editor")}
+                  type="button"
+                >
+                  <Icon name="edit" size="sm" />
+                  <span>Editor</span>
+                </button>
+                <button
+                  className={`mobile-workspace-tab ${mobileTab === "git" ? "active" : ""}`}
+                  onClick={() => setMobileTab("git")}
+                  type="button"
+                >
+                  <Icon name="branch" size="sm" />
+                  <span>Git</span>
+                </button>
+                <button
+                  className={`mobile-workspace-tab ${mobileTab === "terminal" ? "active" : ""}`}
+                  onClick={() => setMobileTab("terminal")}
+                  type="button"
+                >
+                  <Icon name="terminal" size="sm" />
+                  <span>Terminal</span>
+                </button>
+              </div>
+            </div>
+          ) : (
+            // Desktop Layout
+            <>
+              {selectedRepoId && (
+                <GitToolbar
+                  projectId={projectId!}
+                  repoId={selectedRepoId}
+                  currentBranch={currentBranch}
+                  branches={branches}
+                  hasRemote={Boolean(selectedRepo?.remote_url)}
+                  isMirror={Boolean(selectedRepo?.is_mirror)}
+                  onBranchChange={(branch) => {
+                    setCurrentBranch(branch);
+                    const newParams = new URLSearchParams(searchParams);
+                    newParams.set("branch", branch);
+                    setSearchParams(newParams);
+                  }}
+                  onRefresh={() => {
+                    void loadBranches();
+                    void loadGitStatus();
+                    window.dispatchEvent(new CustomEvent("refresh-file-tree"));
+                  }}
+                />
+              )}
+              <div className="workspace-layout">
+                <aside className="workspace-sidebar">
+                  <div className="sidebar-section">
+                    <label className="form-field">
+                      Repository
+                      <select
+                        value={selectedRepoId || ""}
+                        onChange={(e) => handleRepoChange(e.target.value)}
+                      >
+                        {repositories.map((repo) => (
+                          <option key={repo.id} value={repo.id}>
+                            {repo.name}
+                          </option>
+                        ))}
+                      </select>
+                    </label>
+                  </div>
+
+                  {selectedRepoId && (
+                    <>
+                      <FileBrowser
+                        projectId={projectId!}
+                        repoId={selectedRepoId}
+                        gitStatus={gitStatus}
+                      />
+                      {gitStatus && (
+                        <CommitPanel
+                          projectId={projectId!}
+                          repoId={selectedRepoId}
+                          modified={gitStatus.modified}
+                          added={gitStatus.added}
+                          deleted={gitStatus.deleted}
+                          untracked={gitStatus.untracked}
+                          onCommit={() => {
+                            void loadGitStatus();
+                            window.dispatchEvent(new CustomEvent("refresh-file-tree"));
+                          }}
+                        />
+                      )}
+                      <InstanceList
+                        projectId={projectId!}
+                        repoId={selectedRepoId}
+                        projectName={project?.name}
+                        repoName={repositories.find((r) => r.id === selectedRepoId)?.name}
+                        toolTypes={toolTypes}
+                      />
+                    </>
+                  )}
+                </aside>
+
+                <main className="workspace-main">
+                  {selectedRepoId && (
+                    <FileEditor projectId={projectId!} repoId={selectedRepoId} />
+                  )}
+                </main>
+              </div>
+            </>
+          )}
+        </>
       )}
     </section>
   );

apps/web/src/styles.css

@@ -373,3 +373,73 @@
     display: none;
   }
 }
+
+/* Mobile Workspace */
+.mobile-workspace {
+  display: flex;
+  flex-direction: column;
+  height: calc(100vh - 4rem);
+  overflow: hidden;
+}
+
+.mobile-workspace-header {
+  display: flex;
+  gap: var(--space-2);
+  padding: var(--space-2);
+  border-bottom: 1px solid var(--border);
+  background: var(--surface);
+}
+
+.mobile-repo-selector,
+.mobile-branch-selector {
+  flex: 1;
+  padding: var(--space-2);
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  background: var(--surface);
+  color: var(--text);
+  font-size: 0.875rem;
+  min-height: 40px;
+}
+
+.mobile-workspace-content {
+  flex: 1;
+  overflow-y: auto;
+  overflow-x: hidden;
+}
+
+.mobile-workspace-tabs {
+  display: flex;
+  border-top: 1px solid var(--border);
+  background: var(--surface);
+  padding-bottom: env(safe-area-inset-bottom);
+}
+
+.mobile-workspace-tab {
+  flex: 1;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 2px;
+  padding: var(--space-2) var(--space-1);
+  border: none;
+  background: transparent;
+  color: var(--muted);
+  font-size: 0.625rem;
+  cursor: pointer;
+  transition: color 0.15s ease;
+  min-height: 56px;
+}
+
+.mobile-workspace-tab.active {
+  color: var(--brand);
+}
+
+.mobile-workspace-tab:active {
+  opacity: 0.7;
+}
+
+.mobile-git-view {
+  padding: var(--space-2);
+}

openspec/changes/mobile-pages-overhaul/tasks.md

@@ -31,12 +31,12 @@
 
 ## 5. Mobile Repo Workspace
 
-- [ ] 5.1 Create MobileFileTree component with folder expansion
-- [ ] 5.2 Create MobileEditorView component for full-screen editing
-- [ ] 5.3 Create MobileGitView component for git operations
-- [ ] 5.4 Create MobileTerminalView component for terminal access
-- [ ] 5.5 Add bottom tab navigation to RepoWorkspace (Tree, Editor, Git, Terminal)
-- [ ] 5.6 Implement repository and branch selectors for mobile
+- [x] 5.1 Create MobileFileTree component with folder expansion
+- [x] 5.2 Create MobileEditorView component for full-screen editing
+- [x] 5.3 Create MobileGitView component for git operations
+- [x] 5.4 Create MobileTerminalView component for terminal access
+- [x] 5.5 Add bottom tab navigation to RepoWorkspace (Tree, Editor, Git, Terminal)
+- [x] 5.6 Implement repository and branch selectors for mobile
 
 ## 6. Testing & Polish