feat: add View all in folder modal for Resume Conversation (#94)

Drill into a single project's complete history when the homepage's
3-per-project dedup hides older conversations.

- Backend: /api/history/sessions accepts projectKey/offset/limit;
  single-folder mode bypasses the 50-cap and returns { sessions, total }.
  projectKey is validated against ^[A-Za-z0-9_-]+$ to prevent traversal.
- Frontend: detail panel adds "View all in this folder" button that
  opens a modal listing 20 sessions per page with Show more pagination.
- Modal items reuse _buildHistoryItem with showViewAll:false to avoid
  recursive entry points.

Co-authored-by: Teigen <teigen@TeigendeMac-mini.local>

src/web/public/styles.css

@@ -2369,6 +2369,56 @@ body {
   color: var(--text);
 }
 
+.history-detail-actions {
+  margin-top: 0.5rem;
+}
+
+.history-view-all-btn {
+  width: 100%;
+  padding: 0.45rem 0.75rem;
+  background: rgba(99, 179, 237, 0.08);
+  border: 1px solid rgba(99, 179, 237, 0.25);
+  border-radius: 6px;
+  color: rgba(99, 179, 237, 0.95);
+  font-size: 0.78rem;
+  font-weight: 500;
+  cursor: pointer;
+  transition: background var(--transition-smooth), border-color var(--transition-smooth);
+}
+
+.history-view-all-btn:hover {
+  background: rgba(99, 179, 237, 0.15);
+  border-color: rgba(99, 179, 237, 0.5);
+}
+
+/* Folder history modal */
+.folder-history-modal .modal-body {
+  padding: 0.75rem 1rem 1rem;
+}
+
+.folder-history-subtitle {
+  color: var(--text-muted);
+  font-size: 0.78rem;
+  font-family: 'SF Mono', Menlo, Consolas, monospace;
+  word-break: break-all;
+  margin-bottom: 0.75rem;
+  padding-bottom: 0.5rem;
+  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
+}
+
+.folder-history-list {
+  display: flex;
+  flex-direction: column;
+  gap: 0.5rem;
+}
+
+.folder-history-empty {
+  padding: 2rem 0.5rem;
+  text-align: center;
+  color: var(--text-muted);
+  font-size: 0.85rem;
+}
+
 .welcome-hint {
   color: var(--text-muted);
   font-size: 0.8rem;

src/web/public/terminal-ui.js

@@ -917,8 +917,15 @@ Object.assign(CodemanApp.prototype, {
       .replace(/^\/Users\/[^/]+\//, '~/');
   },
 
-  /** Build a single history item DOM element */
-  _buildHistoryItem(s, cases) {
+  /**
+   * Build a single history item DOM element.
+   * @param {object} s session record
+   * @param {Array} cases linked cases (for #caseName label)
+   * @param {object} [options]
+   * @param {boolean} [options.showViewAll=true] show "View all in folder" button in detail panel
+   */
+  _buildHistoryItem(s, cases, options) {
+    const showViewAll = options?.showViewAll !== false;
     const size =
       s.sizeBytes < 1024
         ? `${s.sizeBytes}B`
@@ -1000,6 +1007,21 @@ Object.assign(CodemanApp.prototype, {
 
     detail.append(promptRow, pathRow, metaRow);
 
+    if (showViewAll && s.projectKey) {
+      const actionRow = document.createElement('div');
+      actionRow.className = 'history-detail-row history-detail-actions';
+      const viewAllBtn = document.createElement('button');
+      viewAllBtn.type = 'button';
+      viewAllBtn.className = 'history-view-all-btn';
+      viewAllBtn.textContent = 'View all in this folder';
+      viewAllBtn.addEventListener('click', (ev) => {
+        ev.stopPropagation();
+        this.openFolderHistoryModal(s.projectKey, s.workingDir, cases);
+      });
+      actionRow.appendChild(viewAllBtn);
+      detail.appendChild(actionRow);
+    }
+
     expandBtn.addEventListener('click', (ev) => {
       ev.stopPropagation();
       const expanded = item.classList.toggle('expanded');
@@ -1063,9 +1085,144 @@ Object.assign(CodemanApp.prototype, {
     }
   },
 
+  /** Page size for the folder history modal */
+  _FOLDER_HISTORY_PAGE_SIZE: 20,
+
+  /**
+   * Open a modal showing all history sessions in a single folder.
+   * Paginated by FOLDER_HISTORY_PAGE_SIZE; "Show more" loads next page.
+   */
+  openFolderHistoryModal(projectKey, workingDir, cases) {
+    // Close any existing instance first
+    this._closeFolderHistoryModal();
+
+    const modal = document.createElement('div');
+    modal.className = 'modal active folder-history-modal';
+    modal.id = 'folderHistoryModal';
+
+    const backdrop = document.createElement('div');
+    backdrop.className = 'modal-backdrop';
+    backdrop.addEventListener('click', () => this._closeFolderHistoryModal());
+
+    const content = document.createElement('div');
+    content.className = 'modal-content modal-lg';
+
+    const header = document.createElement('div');
+    header.className = 'modal-header';
+    const title = document.createElement('h3');
+    title.textContent = 'Folder History';
+    const subtitle = document.createElement('div');
+    subtitle.className = 'folder-history-subtitle';
+    subtitle.textContent = this._shortenHomePath(workingDir);
+    const closeBtn = document.createElement('button');
+    closeBtn.className = 'modal-close';
+    closeBtn.setAttribute('aria-label', 'Close');
+    closeBtn.innerHTML = '&times;';
+    closeBtn.addEventListener('click', () => this._closeFolderHistoryModal());
+    header.append(title, closeBtn);
+
+    const body = document.createElement('div');
+    body.className = 'modal-body';
+    const list = document.createElement('div');
+    list.className = 'folder-history-list';
+    list.setAttribute('data-loading', 'true');
+    list.textContent = 'Loading...';
+    body.append(subtitle, list);
+
+    content.append(header, body);
+    modal.append(backdrop, content);
+    document.body.appendChild(modal);
+
+    // Track state for pagination
+    this._folderHistoryState = {
+      projectKey,
+      workingDir,
+      cases: cases || [],
+      offset: 0,
+      total: null,
+      list,
+    };
+
+    // ESC to close
+    this._folderHistoryEscHandler = (ev) => {
+      if (ev.key === 'Escape') this._closeFolderHistoryModal();
+    };
+    document.addEventListener('keydown', this._folderHistoryEscHandler);
+
+    this._loadFolderHistoryPage();
+  },
+
+  async _loadFolderHistoryPage() {
+    const state = this._folderHistoryState;
+    if (!state) return;
+    const { projectKey, cases, list } = state;
+    const limit = this._FOLDER_HISTORY_PAGE_SIZE;
+    const offset = state.offset;
+
+    // Remove existing "Show more" button while loading
+    const existingMore = list.querySelector('.folder-history-more');
+    if (existingMore) existingMore.remove();
+
+    // First page: clear loading placeholder
+    if (offset === 0) {
+      list.replaceChildren();
+      list.removeAttribute('data-loading');
+    }
+
+    try {
+      const url = `/api/history/sessions?projectKey=${encodeURIComponent(projectKey)}&offset=${offset}&limit=${limit}`;
+      const res = await fetch(url);
+      const data = await res.json();
+      const sessions = data.sessions || [];
+      state.total = typeof data.total === 'number' ? data.total : sessions.length + offset;
+
+      if (offset === 0 && sessions.length === 0) {
+        const empty = document.createElement('div');
+        empty.className = 'folder-history-empty';
+        empty.textContent = 'No conversations found in this folder.';
+        list.appendChild(empty);
+        return;
+      }
+
+      for (const s of sessions) {
+        list.appendChild(this._buildHistoryItem(s, cases, { showViewAll: false }));
+      }
+
+      state.offset = offset + sessions.length;
+
+      // Add "Show more" if there are more sessions
+      if (state.offset < state.total) {
+        const remaining = state.total - state.offset;
+        const moreBtn = document.createElement('button');
+        moreBtn.className = 'history-show-more folder-history-more';
+        moreBtn.textContent = `Show ${Math.min(limit, remaining)} more (${remaining} remaining)`;
+        moreBtn.addEventListener('click', () => this._loadFolderHistoryPage());
+        list.appendChild(moreBtn);
+      }
+    } catch (err) {
+      console.error('[loadFolderHistoryPage]', err);
+      const errorEl = document.createElement('div');
+      errorEl.className = 'folder-history-empty';
+      errorEl.textContent = 'Failed to load folder history.';
+      list.appendChild(errorEl);
+    }
+  },
+
+  _closeFolderHistoryModal() {
+    const modal = document.getElementById('folderHistoryModal');
+    if (modal) modal.remove();
+    if (this._folderHistoryEscHandler) {
+      document.removeEventListener('keydown', this._folderHistoryEscHandler);
+      this._folderHistoryEscHandler = null;
+    }
+    this._folderHistoryState = null;
+  },
+
   async resumeHistorySession(sessionId, workingDir) {
     // Close the run mode menu if open
     document.getElementById('runModeMenu')?.classList.remove('active');
+    // Close folder history modal if open
+    this._closeFolderHistoryModal();
     try {
       this.terminal.clear();
       this.terminal.writeln(`\x1b[1;32m Resuming conversation ${sessionId.slice(0, 8)}...\x1b[0m`);

src/web/routes/session-routes.ts

@@ -1448,96 +1448,104 @@ export function registerSessionRoutes(
     }
   }
 
-  app.get('/api/history/sessions', async () => {
+  type HistorySession = {
+    sessionId: string;
+    workingDir: string;
+    projectKey: string;
+    sizeBytes: number;
+    lastModified: string;
+    firstPrompt?: string;
+  };
+
+  // Scan a single project directory and return all valid history sessions in it.
+  // Reused by both the global overview and the single-folder drill-down.
+  async function scanProjectDir(projPath: string, projDir: string, headBuf: Buffer): Promise<HistorySession[]> {
+    const out: HistorySession[] = [];
+    const stat = await fs.stat(projPath).catch(() => null);
+    if (!stat?.isDirectory()) return out;
+
+    const workingDir = await decodeProjectKey(projDir);
+    const entries = await fs.readdir(projPath).catch(() => [] as string[]);
+
+    for (const entry of entries) {
+      if (!entry.endsWith('.jsonl')) continue;
+      const sessionId = entry.replace('.jsonl', '');
+      if (!/^[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$/.test(sessionId)) continue;
+
+      const filePath = join(projPath, entry);
+      const fileStat = await fs.stat(filePath).catch(() => null);
+      if (!fileStat) continue;
+      if (fileStat.size < 4000) continue;
+
+      let firstPrompt: string | undefined;
+      const head = await readFileHead(filePath, headBuf);
+      const hasConversation = (text: string) =>
+        text.includes('"type":"user"') || text.includes('"type":"assistant"') || text.includes('"type":"summary"');
+
+      let foundContent = head ? hasConversation(head) : false;
+      let tail: string | null = null;
+      if (!foundContent && fileStat.size > 16384) {
+        const tailBuf = Buffer.alloc(32768);
+        tail = await readFileTail(filePath, tailBuf, fileStat.size);
+        if (tail) foundContent = hasConversation(tail);
+      }
+      if (!foundContent) continue;
+
+      if (head) firstPrompt = extractFirstUserPrompt(head);
+      if (!firstPrompt && fileStat.size > 65536) {
+        if (!tail) {
+          const tailBuf = Buffer.alloc(32768);
+          tail = await readFileTail(filePath, tailBuf, fileStat.size);
+        }
+        if (tail) firstPrompt = extractFirstUserPrompt(tail);
+      }
+
+      out.push({
+        sessionId,
+        workingDir,
+        projectKey: projDir,
+        sizeBytes: fileStat.size,
+        lastModified: fileStat.mtime.toISOString(),
+        firstPrompt,
+      });
+    }
+    return out;
+  }
+
+  app.get('/api/history/sessions', async (req) => {
+    const query = req.query as { projectKey?: string; offset?: string; limit?: string };
     const projectsDir = join(process.env.HOME || '/tmp', '.claude', 'projects');
-    const results: Array<{
-      sessionId: string;
-      workingDir: string;
-      projectKey: string;
-      sizeBytes: number;
-      lastModified: string;
-      firstPrompt?: string;
-    }> = [];
     const headBuf = Buffer.alloc(16384);
 
+    // Single-folder drill-down: when projectKey is provided, scan only that
+    // directory, bypass the 50-cap, and honor offset/limit pagination.
+    if (query.projectKey) {
+      // Validate projectKey format to prevent path traversal
+      if (!/^[A-Za-z0-9_-]+$/.test(query.projectKey)) {
+        return { sessions: [], total: 0 };
+      }
+      const offset = Math.max(0, parseInt(query.offset || '0', 10) || 0);
+      const limit = Math.min(100, Math.max(1, parseInt(query.limit || '20', 10) || 20));
+      const projPath = join(projectsDir, query.projectKey);
+      const all = await scanProjectDir(projPath, query.projectKey, headBuf);
+      all.sort((a, b) => new Date(b.lastModified).getTime() - new Date(a.lastModified).getTime());
+      return { sessions: all.slice(offset, offset + limit), total: all.length };
+    }
+
+    // Global overview: scan all projects, return up to 50 most-recent sessions.
+    const results: HistorySession[] = [];
     try {
       const projectDirs = await fs.readdir(projectsDir);
       for (const projDir of projectDirs) {
         const projPath = join(projectsDir, projDir);
-        const stat = await fs.stat(projPath).catch(() => null);
-        if (!stat?.isDirectory()) continue;
-
-        // Decode project key to working dir. Claude CLI encodes '/' as '-',
-        // but path components may also contain '-' (e.g. "AI_project" vs "AI-project").
-        // Use recursive backtracking: try each '-' as either '/' or literal '-',
-        // verify which decoded path actually exists on disk.
-        const workingDir = await decodeProjectKey(projDir);
-
-        const entries = await fs.readdir(projPath);
-        for (const entry of entries) {
-          if (!entry.endsWith('.jsonl')) continue;
-          const sessionId = entry.replace('.jsonl', '');
-          // Only valid UUIDs
-          if (!/^[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$/.test(sessionId)) continue;
-
-          const filePath = join(projPath, entry);
-          const fileStat = await fs.stat(filePath).catch(() => null);
-          if (!fileStat) continue;
-          // Skip files too small to contain real conversation (metadata-only sessions
-          // like file-history-snapshot entries are typically < 4KB)
-          if (fileStat.size < 4000) continue;
-
-          // Quick content check: verify actual conversation data exists.
-          // Sessions with only file-history-snapshot or hook_progress entries have
-          // no "user"/"assistant" messages and will fail claude --resume.
-          // Read first 16KB to check content and extract first user prompt.
-          let firstPrompt: string | undefined;
-          const head = await readFileHead(filePath, headBuf);
-          const hasConversation = (text: string) =>
-            text.includes('"type":"user"') || text.includes('"type":"assistant"') || text.includes('"type":"summary"');
-
-          let foundContent = head ? hasConversation(head) : false;
-
-          // For large files, head may not contain user messages (e.g. /init followed
-          // by large system entries). Check the tail as well.
-          let tail: string | null = null;
-          if (!foundContent && fileStat.size > 16384) {
-            const tailBuf = Buffer.alloc(32768);
-            tail = await readFileTail(filePath, tailBuf, fileStat.size);
-            if (tail) foundContent = hasConversation(tail);
-          }
-
-          if (!foundContent) continue; // No conversation content — skip
-
-          if (head) firstPrompt = extractFirstUserPrompt(head);
-
-          // If head scan found no usable prompt (e.g. session started with /init),
-          // try reading the tail for a recent user message.
-          if (!firstPrompt && fileStat.size > 65536) {
-            if (!tail) {
-              const tailBuf = Buffer.alloc(32768);
-              tail = await readFileTail(filePath, tailBuf, fileStat.size);
-            }
-            if (tail) firstPrompt = extractFirstUserPrompt(tail);
-          }
-
-          results.push({
-            sessionId,
-            workingDir,
-            projectKey: projDir,
-            sizeBytes: fileStat.size,
-            lastModified: fileStat.mtime.toISOString(),
-            firstPrompt,
-          });
-        }
+        const list = await scanProjectDir(projPath, projDir, headBuf);
+        results.push(...list);
       }
     } catch {
       // Projects dir may not exist
     }
 
-    // Sort by lastModified descending
     results.sort((a, b) => new Date(b.lastModified).getTime() - new Date(a.lastModified).getTime());
-
     return { sessions: results.slice(0, 50) };
   });