fix: remove dead delete+recreate and pin code, add poll fallback test

Phase 1 cleanup:
- Remove deletePost() method (dead code, replaced by PUT in-place updates)
- Remove _postInfo Map tracking (no longer needed)
- Remove pin/unpin API calls from watcher-manager.js (incompatible with PUT updates)
- Add JSDoc note on (edited) label limitation in _flushUpdate()
- Add integration test: test/integration/poll-fallback.test.js
- Fix addSession() lastOffset===0 falsy bug (0 was treated as 'no offset')
- Fix pre-existing test failures: add lastOffset:0 where tests expect backlog reads
- Fix pre-existing session-monitor test: create stub transcript files
- Fix pre-existing status-formatter test: update indent check for blockquote format
- Format plugin/ files with Prettier (pre-existing formatting drift)

src/session-monitor.js

@@ -276,7 +276,10 @@ class SessionMonitor extends EventEmitter {
     } catch (_e) {
       // File doesn't exist — skip silently
       if (this.logger) {
-        this.logger.debug({ sessionKey, transcriptFile }, 'Skipping session (transcript not found)');
+        this.logger.debug(
+          { sessionKey, transcriptFile },
+          'Skipping session (transcript not found)',
+        );
       }
       return;
     }

src/status-box.js

@@ -76,10 +76,6 @@ class StatusBox extends EventEmitter {
     // Throttle state per postId
     // Map<postId, { pending: string|null, timer: NodeJS.Timeout|null, lastFiredAt: number }>
     this._throttleState = new Map();
-
-    // Track post metadata for delete+recreate
-    // Map<postId, { channelId, rootId }>
-    this._postInfo = new Map();
   }
 
   /**
@@ -97,9 +93,6 @@ class StatusBox extends EventEmitter {
     if (this.logger) this.logger.debug({ postId: post.id, channelId }, 'Created status post');
     this.metrics.updatesSent++;
 
-    // Track post info for delete+recreate
-    this._postInfo.set(post.id, { channelId, rootId: rootId || null });
-
     return post.id;
   }
 
@@ -145,6 +138,9 @@ class StatusBox extends EventEmitter {
   /**
    * Flush the pending update for a postId.
    * @private
+   * Note: PUT updates cause Mattermost to show '(edited)' label on the post.
+   * This is a known API limitation. The Mattermost plugin (Phase 3) solves this
+   * via custom post type rendering.
    */
   async _flushUpdate(postId) {
     const state = this._throttleState.get(postId);
@@ -163,7 +159,7 @@ class StatusBox extends EventEmitter {
     this.metrics.queueDepth = Math.max(0, this.metrics.queueDepth - 1);
 
     try {
-      // In-place PUT update — no delete+recreate, no flicker
+      // In-place PUT update
       await this._apiCallWithRetry('PUT', `/api/v4/posts/${postId}`, {
         id: postId,
         message: this._truncate(text),
@@ -202,15 +198,6 @@ class StatusBox extends EventEmitter {
     await Promise.allSettled(postIds.map((id) => this.forceFlush(id)));
   }
 
-  /**
-   * Delete a post.
-   * @param {string} postId
-   * @returns {Promise<void>}
-   */
-  async deletePost(postId) {
-    await this._apiCall('DELETE', `/api/v4/posts/${postId}`, null);
-  }
-
   /**
    * Truncate text to maxMessageChars.
    * @private

src/status-formatter.js

@@ -70,7 +70,12 @@ function format(sessionState, opts = {}) {
   // never collapses like code blocks do, supports inline markdown
   var body = lines.join('\n');
   if (depth === 0) {
-    body = body.split('\n').map(function (l) { return '> ' + l; }).join('\n');
+    body = body
+      .split('\n')
+      .map(function (l) {
+        return '> ' + l;
+      })
+      .join('\n');
   }
   return body;
 }

src/status-watcher.js

@@ -52,9 +52,12 @@ class StatusWatcher extends EventEmitter {
     if (this.sessions.has(sessionKey)) return;
 
     // For new sessions (no saved offset), start from current file position
-    // so we only show NEW content going forward — not the entire backlog
-    let startOffset = initialState.lastOffset || 0;
-    if (!initialState.lastOffset) {
+    // so we only show NEW content going forward — not the entire backlog.
+    // Pass lastOffset: 0 explicitly to read from the beginning.
+    var startOffset;
+    if (initialState.lastOffset !== undefined) {
+      startOffset = initialState.lastOffset;
+    } else {
       try {
         var stat = fs.statSync(transcriptFile);
         startOffset = stat.size;
@@ -86,8 +89,8 @@ class StatusWatcher extends EventEmitter {
       this.logger.debug({ sessionKey, transcriptFile, startOffset }, 'Session added to watcher');
     }
 
-    // Only read if we have a saved offset (recovery) — new sessions start streaming from current position
-    if (initialState.lastOffset) {
+    // Only read if we have an explicit offset (recovery or explicit 0) — new sessions start streaming from current position
+    if (initialState.lastOffset !== undefined) {
       this._readFile(sessionKey, state);
     }
 
@@ -327,9 +330,7 @@ class StatusWatcher extends EventEmitter {
                 argStr = item.arguments.url.slice(0, 60);
               }
             }
-            var statusLine = argStr
-              ? toolName + ': ' + argStr
-              : toolName + ': ' + label;
+            var statusLine = argStr ? toolName + ': ' + argStr : toolName + ': ' + label;
             state.lines.push(statusLine);
           } else if (item.type === 'text' && item.text) {
             var text = item.text.trim();

src/watcher-manager.js

@@ -240,14 +240,6 @@ async function startDaemon() {
         const initialText = buildInitialText(agentId, sessionKey);
         postId = await sharedStatusBox.createPost(channelId, initialText, rootPostId);
         logger.info({ sessionKey, postId, channelId }, 'Created status box');
-
-        // Auto-pin the status post so it's always visible
-        try {
-          await sharedStatusBox._apiCall('POST', '/api/v4/posts/' + postId + '/pin', {});
-          logger.debug({ sessionKey, postId }, 'Status post pinned');
-        } catch (pinErr) {
-          logger.warn({ sessionKey, err: pinErr }, 'Failed to pin status post');
-        }
       } catch (err) {
         logger.error({ sessionKey, err }, 'Failed to create status post');
         globalMetrics.lastError = err.message;
@@ -339,14 +331,6 @@ async function startDaemon() {
       logger.error({ sessionKey, err }, 'Failed to update final status');
     }
 
-    // Unpin the status post when session is done
-    try {
-      await sharedStatusBox._apiCall('POST', `/api/v4/posts/${box.postId}/unpin`, {});
-      logger.debug({ sessionKey, postId: box.postId }, 'Status post unpinned');
-    } catch (unpinErr) {
-      logger.warn({ sessionKey, err: unpinErr }, 'Failed to unpin status post');
-    }
-
     // Clean up — remove from all tracking so session can be re-detected if it becomes active again
     activeBoxes.delete(sessionKey);
     watcher.removeSession(sessionKey);