feat: Add mobile task index with 11ty build-time data

Phase 2 of task management consolidation:

- Added _data/tasks.js - fetches tasks from Gitea API at build time
- Added tasks-index.njk - mobile-friendly task list page
- Added node-fetch dependency for API calls
- Added .gitignore for node_modules and _site

Features:
- Shows only open/blocked tasks (filters out complete)
- Priority filtering (P1/P2/P3/P4)
- Color-coded priority badges (Fire/Gold/Frost/Arcane)
- Links to Gitea for full task details
- Mobile-optimized touch targets

Access at: firefrostgaming.com/tasks-index.html

Chronicler #69

package-lock.json

@@ -8,6 +8,9 @@
       "name": "firefrost-website",
       "version": "1.0.0",
       "license": "ISC",
+      "dependencies": {
+        "node-fetch": "^2.7.0"
+      },
       "devDependencies": {
         "@11ty/eleventy": "^3.0.0"
       }
@@ -1218,6 +1221,26 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/node-fetch": {
+      "version": "2.7.0",
+      "resolved": "https://registry.npmjs.org/node-fetch/-/node-fetch-2.7.0.tgz",
+      "integrity": "sha512-c4FRfUm/dbcWZ7U+1Wq0AwCyFL+3nt2bEw05wfxSz+DWpWsitgmSgYmy2dQdWyKC1694ELPqMs/YzUSNozLt8A==",
+      "license": "MIT",
+      "dependencies": {
+        "whatwg-url": "^5.0.0"
+      },
+      "engines": {
+        "node": "4.x || >=6.0.0"
+      },
+      "peerDependencies": {
+        "encoding": "^0.1.0"
+      },
+      "peerDependenciesMeta": {
+        "encoding": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/node-retrieve-globals": {
       "version": "6.0.1",
       "resolved": "https://registry.npmjs.org/node-retrieve-globals/-/node-retrieve-globals-6.0.1.tgz",
@@ -1603,6 +1626,12 @@
         "node": ">=0.6"
       }
     },
+    "node_modules/tr46": {
+      "version": "0.0.3",
+      "resolved": "https://registry.npmjs.org/tr46/-/tr46-0.0.3.tgz",
+      "integrity": "sha512-N3WMsuqV66lT30CrXNbEjx4GEwlow3v6rr4mCcv6prnfwhS01rkgyFdjPNBYd9br7LpXV1+Emh01fHnq2Gdgrw==",
+      "license": "MIT"
+    },
     "node_modules/uc.micro": {
       "version": "2.1.0",
       "resolved": "https://registry.npmjs.org/uc.micro/-/uc.micro-2.1.0.tgz",
@@ -1627,6 +1656,22 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/webidl-conversions": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/webidl-conversions/-/webidl-conversions-3.0.1.tgz",
+      "integrity": "sha512-2JAn3z8AR6rjK8Sm8orRC0h/bcl/DqL7tRPdGZ4I1CjdF+EaMLmYxBHyXuKL849eucPFhvBoxMsflfOb8kxaeQ==",
+      "license": "BSD-2-Clause"
+    },
+    "node_modules/whatwg-url": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/whatwg-url/-/whatwg-url-5.0.0.tgz",
+      "integrity": "sha512-saE57nupxk6v3HY35+jzBwYa0rKSy0XR8JSxZPwgLr7ys0IBzhGviA1/TUGJLmSVqs8pb9AnvICXEuOHLprYTw==",
+      "license": "MIT",
+      "dependencies": {
+        "tr46": "~0.0.3",
+        "webidl-conversions": "^3.0.0"
+      }
+    },
     "node_modules/ws": {
       "version": "8.20.0",
       "resolved": "https://registry.npmjs.org/ws/-/ws-8.20.0.tgz",