Add super-fast dumpToTerminal method to CastConverter

- Added dumpToTerminal() method that builds entire cast content into one string and writes it all at once for maximum performance
- Handles resize ('r') events by tracking final terminal dimensions and applying them before writing content
- Processes output ('o') events into a single concatenated string for the fastest possible loading
- Ignores input ('i') events during dump as they're not needed for display
- Updated session cards to use the new fast dump method instead of manual parsing
- Results in dramatically faster session card loading and refresh

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

web/src/client/components/session-card.ts

@@ -2,6 +2,7 @@ import { LitElement, html, PropertyValues } from 'lit';
 import { customElement, property, state } from 'lit/decorators.js';
 import './terminal.js';
 import type { Terminal } from './terminal.js';
+import { CastConverter } from '../utils/cast-converter.js';
 
 export interface Session {
   id: string;
@@ -99,25 +100,11 @@ export class SessionCard extends LitElement {
 
       const castContent = await response.text();
 
-      // Clear terminal and write snapshot data
+      // Clear terminal first
       this.terminal.clear();
 
-      // Parse cast file and write content
-      const lines = castContent.trim().split('\n');
-      for (const line of lines) {
-        if (line.trim()) {
-          try {
-            const event = JSON.parse(line);
-            if (event.length >= 3 && event[1] === 'o') {
-              // Output event: [timestamp, 'o', data]
-              this.terminal.write(event[2], false); // Don't follow cursor for snapshot
-            }
-          } catch (_e) {
-            // Skip invalid lines
-            continue;
-          }
-        }
-      }
+      // Use the new super-fast dump method that handles everything in one operation
+      await CastConverter.dumpToTerminal(this.terminal, castContent);
 
       // Scroll to bottom after loading
       this.terminal.queueCallback(() => {

web/src/client/utils/cast-converter.ts

@@ -208,4 +208,56 @@ export class CastConverter {
       }
     }
   }
+
+  /**
+   * Dump entire cast content to terminal instantly as a single write operation.
+   * This is the fastest way to load cast content - builds one string and writes it all at once.
+   * Handles resize events by applying the final dimensions to the terminal.
+   *
+   * @param terminal - DOM terminal instance with write() and setTerminalSize() methods
+   * @param castContent - Raw cast file content
+   * @returns Promise that resolves when dump is complete
+   */
+  static async dumpToTerminal(
+    terminal: {
+      write: (data: string, followCursor?: boolean) => void;
+      setTerminalSize?: (cols: number, rows: number) => void;
+    },
+    castContent: string
+  ): Promise<void> {
+    const converted = this.convertCast(castContent);
+
+    // Track final terminal dimensions from resize events
+    let finalCols = converted.header?.width || 80;
+    let finalRows = converted.header?.height || 24;
+
+    // Build up output string and track final resize dimensions
+    const outputChunks: string[] = [];
+
+    for (const event of converted.events) {
+      if (event.type === 'o') {
+        // Output event - add to content
+        outputChunks.push(event.data);
+      } else if (event.type === 'r') {
+        // Resize event - track final dimensions
+        const match = event.data.match(/^(\d+)x(\d+)$/);
+        if (match) {
+          finalCols = parseInt(match[1], 10);
+          finalRows = parseInt(match[2], 10);
+        }
+      }
+      // Ignore 'i' (input) events for dump
+    }
+
+    // Apply final terminal size first if we have resize capability
+    if (terminal.setTerminalSize) {
+      terminal.setTerminalSize(finalCols, finalRows);
+    }
+
+    // Write all content at once as a single operation (fastest possible)
+    const allContent = outputChunks.join('');
+    if (allContent) {
+      terminal.write(allContent, false); // Don't follow cursor during dump for performance
+    }
+  }
 }