feat: improve chunk viewer with fixed navigation and markdown rendering

This commit implements three UI improvements for the chunk viewer:

1. Fixed modal footer with navigation controls
   - Moved PDF navigation buttons to a fixed footer
   - Footer remains visible while scrolling content
   - Three-section layout: fixed header, scrollable body, fixed footer

2. Removed duplicate navigation controls
   - Removed previous/next buttons from PDFViewer component
   - Controls now only in App.vue modal footer
   - Cleaned up unused imports and CSS

3. Markdown rendering for chunk content
   - Created MarkdownViewer component using markdown-it
   - Renders markdown content aligned with Nextcloud design system
   - Removed problematic markdown-it-task-checkbox dependency
   - Combines before/chunk/after context with visual separators

4. Cleaned up search results display
   - Removed excerpt snippets from results list
   - Kept only chunk/page metadata for cleaner UI

The modal structure now has:
- Fixed header (title + close button)
- Scrollable body (PDF canvas or markdown content)
- Fixed footer (page navigation - always visible)

Fixes markdown rendering "require is not defined" error by using
only markdown-it without CommonJS plugins.

third_party/astroglobe/package-lock.json

@@ -13,6 +13,7 @@
         "@nextcloud/l10n": "^3.1.0",
         "@nextcloud/router": "^3.0.1",
         "@nextcloud/vue": "^8.29.2",
+        "markdown-it": "^14.1.0",
         "pdfjs-dist": "^4.0.379",
         "plotly.js-dist-min": "^2.35.3",
         "vue": "^2.7.16",
@@ -4113,9 +4114,7 @@
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/argparse/-/argparse-2.0.1.tgz",
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-      "dev": true,
-      "license": "Python-2.0",
-      "peer": true
+      "license": "Python-2.0"
     },
     "node_modules/array-buffer-byte-length": {
       "version": "1.0.2",
@@ -5722,7 +5721,6 @@
       "version": "4.5.0",
       "resolved": "https://registry.npmjs.org/entities/-/entities-4.5.0.tgz",
       "integrity": "sha512-V0hjH4dGPh9Ao5p0MoRY6BVqtwCjhz6vI5LT8AJ55H+4g9/4vbHx1I54fS0XuclLhDHArPQCiMjDxjaL8fPxhw==",
-      "dev": true,
       "license": "BSD-2-Clause",
       "engines": {
         "node": ">=0.12"
@@ -8622,6 +8620,15 @@
       "license": "MIT",
       "peer": true
     },
+    "node_modules/linkify-it": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/linkify-it/-/linkify-it-5.0.0.tgz",
+      "integrity": "sha512-5aHCbzQRADcdP+ATqnDuhhJ/MRIqDkZX5pyjFHRRysS8vZ5AbqGEoFIb6pYHPZ+L/OC2Lc+xT8uHVVR5CAK/wQ==",
+      "license": "MIT",
+      "dependencies": {
+        "uc.micro": "^2.0.0"
+      }
+    },
     "node_modules/linkify-string": {
       "version": "4.3.2",
       "resolved": "https://registry.npmjs.org/linkify-string/-/linkify-string-4.3.2.tgz",
@@ -8737,6 +8744,23 @@
         "@jridgewell/sourcemap-codec": "^1.5.5"
       }
     },
+    "node_modules/markdown-it": {
+      "version": "14.1.0",
+      "resolved": "https://registry.npmjs.org/markdown-it/-/markdown-it-14.1.0.tgz",
+      "integrity": "sha512-a54IwgWPaeBCAAsv13YgmALOF1elABB08FxO9i+r4VFk5Vl4pKokRPeX8u5TCgSsPi6ec1otfLjdOpVcgbpshg==",
+      "license": "MIT",
+      "dependencies": {
+        "argparse": "^2.0.1",
+        "entities": "^4.4.0",
+        "linkify-it": "^5.0.0",
+        "mdurl": "^2.0.0",
+        "punycode.js": "^2.3.1",
+        "uc.micro": "^2.1.0"
+      },
+      "bin": {
+        "markdown-it": "bin/markdown-it.mjs"
+      }
+    },
     "node_modules/material-colors": {
       "version": "1.2.6",
       "resolved": "https://registry.npmjs.org/material-colors/-/material-colors-1.2.6.tgz",
@@ -8909,6 +8933,12 @@
       "license": "CC0-1.0",
       "peer": true
     },
+    "node_modules/mdurl": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/mdurl/-/mdurl-2.0.0.tgz",
+      "integrity": "sha512-Lf+9+2r+Tdp5wXDXC4PcIBjTDtq4UKjCPMQhKIuzpJNW0b96kVqSwW0bT7FhRSfmAiFYgP+SCRvdrDozfh0U5w==",
+      "license": "MIT"
+    },
     "node_modules/meow": {
       "version": "13.2.0",
       "resolved": "https://registry.npmjs.org/meow/-/meow-13.2.0.tgz",
@@ -10414,6 +10444,15 @@
         "node": ">=6"
       }
     },
+    "node_modules/punycode.js": {
+      "version": "2.3.1",
+      "resolved": "https://registry.npmjs.org/punycode.js/-/punycode.js-2.3.1.tgz",
+      "integrity": "sha512-uxFIHU0YlHYhDQtV4R9J6a52SLx28BCjT+4ieh7IGbgwVJWO+km431c4yRlREUAsAmt/uMjQUyQHNEPf0M39CA==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=6"
+      }
+    },
     "node_modules/qified": {
       "version": "0.5.3",
       "resolved": "https://registry.npmjs.org/qified/-/qified-0.5.3.tgz",
@@ -12669,6 +12708,12 @@
       "license": "MIT",
       "optional": true
     },
+    "node_modules/uc.micro": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/uc.micro/-/uc.micro-2.1.0.tgz",
+      "integrity": "sha512-ARDJmphmdvUk6Glw7y9DQ2bFkKBHwQHLi2lsaH6PPmz/Ka9sFOBsBluozhDltWmnv9u/cF6Rt87znRTPV+yp/A==",
+      "license": "MIT"
+    },
     "node_modules/ufo": {
       "version": "1.6.1",
       "resolved": "https://registry.npmjs.org/ufo/-/ufo-1.6.1.tgz",