feat: add AI deadline extraction frontend page (Phase 2M)

- ExtractionForm: PDF dropzone (react-dropzone) + text textarea + case selector
- ExtractionResults: review table with edit/remove per row, confidence color-coding
- Page at /ai/extract: upload -> analyze -> review -> adopt deadlines to case
- Extended API client with postFormData for multipart uploads
- Added ExtractedDeadline and ExtractionResponse types

frontend/bun.lock

@@ -13,6 +13,7 @@
         "next": "15.5.14",
         "react": "19.1.0",
         "react-dom": "19.1.0",
+        "react-dropzone": "^15.0.0",
         "sonner": "^2.0.7",
       },
       "devDependencies": {
@@ -315,6 +316,8 @@
 
     "async-function": ["async-function@1.0.0", "", {}, "sha512-hsU18Ae8CDTR6Kgu9DYf0EbCr/a5iGL0rytQDobUcdpYOKokk8LEjVphnXkDkgpi0wYVsqrXuP0bZxJaTqdgoA=="],
 
+    "attr-accept": ["attr-accept@2.2.5", "", {}, "sha512-0bDNnY/u6pPwHDMoF0FieU354oBi0a8rD9FcsLwzcGWbc8KS8KPIi7y+s13OlVY+gMWc/9xEMUgNE6Qm8ZllYQ=="],
+
     "available-typed-arrays": ["available-typed-arrays@1.0.7", "", { "dependencies": { "possible-typed-array-names": "^1.0.0" } }, "sha512-wvUjBtSGN7+7SjNpq/9M2Tg350UZD3q62IFZLbRAR1bSMlCo1ZaeW+BJ+D090e4hIIZLBcTDWe4Mh4jvUDajzQ=="],
 
     "axe-core": ["axe-core@4.11.1", "", {}, "sha512-BASOg+YwO2C+346x3LZOeoovTIoTrRqEsqMa6fmfAV0P+U9mFr9NsyOEpiYvFjbc64NMrSswhV50WdXzdb/Z5A=="],
@@ -445,6 +448,8 @@
 
     "file-entry-cache": ["file-entry-cache@8.0.0", "", { "dependencies": { "flat-cache": "^4.0.0" } }, "sha512-XXTUwCvisa5oacNGRP9SfNtYBNAMi+RPwBFmblZEF7N7swHYQS6/Zfk7SRwx4D5j3CH211YNRco1DEMNVfZCnQ=="],
 
+    "file-selector": ["file-selector@2.1.2", "", { "dependencies": { "tslib": "^2.7.0" } }, "sha512-QgXo+mXTe8ljeqUFaX3QVHc5osSItJ/Km+xpocx0aSqWGMSCf6qYs/VnzZgS864Pjn5iceMRFigeAV7AfTlaig=="],
+
     "fill-range": ["fill-range@7.1.1", "", { "dependencies": { "to-regex-range": "^5.0.1" } }, "sha512-YsGpe3WHLK8ZYi4tWDg2Jy3ebRz2rXowDxnld4bkQB00cc/1Zw9AWnC0i9ztDJitivtQvaI9KaLyKrc+hBW0yg=="],
 
     "find-up": ["find-up@5.0.0", "", { "dependencies": { "locate-path": "^6.0.0", "path-exists": "^4.0.0" } }, "sha512-78/PXT1wlLLDgTzDs7sjq9hzz0vXD+zn+7wypEe4fXQxCmdmqfGsEPQxmiCSQI3ajFV91bVSsvNtrJRiW6nGng=="],
@@ -695,6 +700,8 @@
 
     "react-dom": ["react-dom@19.1.0", "", { "dependencies": { "scheduler": "^0.26.0" }, "peerDependencies": { "react": "^19.1.0" } }, "sha512-Xs1hdnE+DyKgeHJeJznQmYMIBG3TKIHJJT95Q58nHLSrElKlGQqDTR2HQ9fx5CN/Gk6Vh/kupBTDLU11/nDk/g=="],
 
+    "react-dropzone": ["react-dropzone@15.0.0", "", { "dependencies": { "attr-accept": "^2.2.4", "file-selector": "^2.1.0", "prop-types": "^15.8.1" }, "peerDependencies": { "react": ">= 16.8 || 18.0.0" } }, "sha512-lGjYV/EoqEjEWPnmiSvH4v5IoIAwQM2W4Z1C0Q/Pw2xD0eVzKPS359BQTUMum+1fa0kH2nrKjuavmTPOGhpLPg=="],
+
     "react-is": ["react-is@16.13.1", "", {}, "sha512-24e6ynE2H+OKt4kqsOvNd8kBpV65zoxbA4BVsEOB3ARVWQki/DHzaUoC5KuON/BiccDaCCTZBuOcfZs70kR8bQ=="],
 
     "reflect.getprototypeof": ["reflect.getprototypeof@1.0.10", "", { "dependencies": { "call-bind": "^1.0.8", "define-properties": "^1.2.1", "es-abstract": "^1.23.9", "es-errors": "^1.3.0", "es-object-atoms": "^1.0.0", "get-intrinsic": "^1.2.7", "get-proto": "^1.0.1", "which-builtin-type": "^1.2.1" } }, "sha512-00o4I+DVrefhv+nX0ulyi3biSHCPDe+yLv5o/p6d/UVlirijB8E16FtfwSAi4g3tcqrQ4lRAqQSoFEZJehYEcw=="],