feat(astrolabe): enable multi-select for document types and refactor PDF viewer

This commit includes two improvements to the Astroglobe semantic search UI:

1. **Multi-select Document Types** (App.vue):
   - Changed NcCheckboxRadioSwitch binding from v-model to :checked/:update:checked
   - Implemented toggleDocType() method to manually manage selectedDocTypes array
   - Fixes issue where only single document type could be selected at a time
   - Users can now filter search results by multiple doc types simultaneously

2. **PDF Viewer Reactive Rendering** (PDFViewer.vue):
   - Refactored canvas rendering to use Vue reactive watcher pattern
   - Added watcher on 'loading' state that triggers rendering when canvas available
   - Removed imperative renderPage() call from loadPDF() method
   - Inspired by files_pdfviewer's promise/event-based initialization approach
   - Improves alignment with Vue's reactive data flow

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

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

third_party/astroglobe/src/App.vue

@@ -93,9 +93,9 @@
 									<NcCheckboxRadioSwitch
 										v-for="docType in docTypeOptions"
 										:key="docType.id"
-										:checked.sync="selectedDocTypes"
-										:value="docType.id"
-										type="checkbox">
+										:checked="selectedDocTypes.includes(docType.id)"
+										type="checkbox"
+										@update:checked="toggleDocType(docType.id, $event)">
 										{{ docType.label }}
 									</NcCheckboxRadioSwitch>
 								</div>
@@ -469,6 +469,17 @@ export default {
 		},
 	},
 	methods: {
+		toggleDocType(docTypeId, checked) {
+			if (checked && !this.selectedDocTypes.includes(docTypeId)) {
+				this.selectedDocTypes.push(docTypeId)
+			} else if (!checked) {
+				const index = this.selectedDocTypes.indexOf(docTypeId)
+				if (index > -1) {
+					this.selectedDocTypes.splice(index, 1)
+				}
+			}
+		},
+
 		async performSearch() {
 			const queryText = this.query.trim()
 			if (!queryText) {

third_party/astroglobe/src/components/PDFViewer.vue

@@ -86,6 +86,17 @@ export default {
 			// Reload PDF if file path changes
 			this.loadPDF()
 		},
+		async loading(newLoading) {
+			// When loading completes, wait for canvas to be available and render
+			if (!newLoading && this.pdfDoc && !this.error) {
+				// Wait for Vue to update DOM
+				await this.$nextTick()
+				// Canvas should now be rendered (v-else condition)
+				if (this.$refs.canvas) {
+					await this.renderPage(this.pageNumber)
+				}
+			}
+		},
 	},
 	async mounted() {
 		await this.loadPDF()
@@ -121,16 +132,8 @@ export default {
 				this.totalPages = this.pdfDoc.numPages
 				this.$emit('loaded', { totalPages: this.totalPages })
 
-				// Wait for canvas to be in DOM
-				await this.$nextTick()
-
-				// Canvas should be available now (mounted lifecycle guarantees it)
-				if (!this.$refs.canvas) {
-					throw new Error('Canvas element not available after mount')
-				}
-
-				// Render the requested page
-				await this.renderPage(this.pageNumber)
+				// Set loading to false - the watcher will handle rendering
+				this.loading = false
 			} catch (err) {
 				console.error('PDF load error:', err)
 
@@ -148,7 +151,6 @@ export default {
 				}
 
 				this.$emit('error', err)
-			} finally {
 				this.loading = false
 			}
 		},