feat: Add patchset history and diff support with cvsps integration

- Add cvsps package to Docker dependencies
- Implement patchset retrieval and diff endpoints in API
- Add _run_cvsps_command() helper for cvsps integration
- Enhance file history parsing with log message extraction
- Improve UI with enhanced styling and patchset functionality

ui/app.js

@@ -158,6 +158,38 @@ class CVSRepositoryBrowser {
         }
     }
 
+    /**
+     * Show patchsets view
+     */
+    async showPatchsets() {
+        try {
+            ui.patchsetContent.innerHTML = '<div class="loading">Loading patchsets...</div>';
+            const patchsets = await api.getPatchsets();
+            ui.displayPatchsets(patchsets);
+        } catch (error) {
+            console.error('Error showing patchsets:', error);
+            ui.patchsetContent.innerHTML = `<div class="loading" style="color: #991b1b;">Error loading patchsets: ${error.message}</div>`;
+            ui.showView(ui.patchsetView);
+        }
+    }
+
+    /**
+     * Show patchset diff
+     * @param {string} patchset - Patchset number
+     */
+    async showPatchsetDiff(patchset) {
+        try {
+            ui.patchsetDiffContent.innerHTML = '<div class="loading">Loading patchset diff...</div>';
+            const diffResult = await api.getPatchsetDiff(patchset);
+            const diffText = diffResult.diff || diffResult;
+            ui.displayPatchsetDiff(diffText);
+        } catch (error) {
+            console.error('Error showing patchset diff:', error);
+            ui.patchsetDiffContent.innerHTML = `<div class="loading" style="color: #991b1b;">Error loading patchset diff: ${error.message}</div>`;
+            ui.showView(ui.patchsetDiffView);
+        }
+    }
+
     /**
      * Setup event listeners
      */
@@ -176,6 +208,17 @@ class CVSRepositoryBrowser {
         ui.backFromDiffBtn.addEventListener('click', () => {
             ui.showView(ui.fileView);
         });
+
+        // Patchset view buttons
+        ui.patchsetsBtn.addEventListener('click', () => this.showPatchsets());
+        ui.backFromPatchsetBtn.addEventListener('click', () => {
+            ui.showView(ui.welcomeView);
+        });
+
+        // Patchset diff view back button
+        ui.backFromPatchsetDiffBtn.addEventListener('click', () => {
+            ui.showView(ui.patchsetView);
+        });
     }
 }