feat(projects): 설명 마크다운 렌더링 + 저장소 README 가져오기

등록 모달의 '한 줄 설명' input 을 여러 줄 textarea 로 바꾸고, 설명을
markdown-it 로 렌더링한다(html:false 로 raw HTML 이스케이프·javascript:
링크 차단 — XSS 안전). 상세 화면은 마크다운으로, 카드 미리보기는 기호를
걷어낸 순수 텍스트(mdPlain) + 3줄 클램프로 표시.

'저장소 README 가져오기' 버튼과 GET /api/readme 라우트를 추가해 repo_url
의 Gitea README 를 설명란으로 불러올 수 있다(gitea.js fetchReadme).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

package-lock.json

@@ -12,6 +12,7 @@
         "ejs": "^3.1.10",
         "express": "^4.21.2",
         "express-session": "^1.18.1",
+        "markdown-it": "^14.3.0",
         "openid-client": "^5.7.0",
         "pg": "^8.13.1"
       },
@@ -32,6 +33,12 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/argparse": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/argparse/-/argparse-2.0.1.tgz",
+      "integrity": "sha512-8+9WqebbFzpX9OR+Wa6O29asIogeRMzcGtAINdpMHHyAg10f05aSFVBbcEqGf/PXw1EjAZ+q2/bEBg3DvurK3Q==",
+      "license": "Python-2.0"
+    },
     "node_modules/array-flatten": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/array-flatten/-/array-flatten-1.1.1.tgz",
@@ -242,6 +249,18 @@
         "node": ">= 0.8"
       }
     },
+    "node_modules/entities": {
+      "version": "4.5.0",
+      "resolved": "https://registry.npmjs.org/entities/-/entities-4.5.0.tgz",
+      "integrity": "sha512-V0hjH4dGPh9Ao5p0MoRY6BVqtwCjhz6vI5LT8AJ55H+4g9/4vbHx1I54fS0XuclLhDHArPQCiMjDxjaL8fPxhw==",
+      "license": "BSD-2-Clause",
+      "engines": {
+        "node": ">=0.12"
+      },
+      "funding": {
+        "url": "https://github.com/fb55/entities?sponsor=1"
+      }
+    },
     "node_modules/es-define-property": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/es-define-property/-/es-define-property-1.0.1.tgz",
@@ -562,6 +581,25 @@
         "url": "https://github.com/sponsors/panva"
       }
     },
+    "node_modules/linkify-it": {
+      "version": "5.0.2",
+      "resolved": "https://registry.npmjs.org/linkify-it/-/linkify-it-5.0.2.tgz",
+      "integrity": "sha512-ONTm2jCMAVZjgQa/Fy1kScXsuOoF5NPTsoFBdE1KVIZ2vAh/r9+Bqo+0jINCBYnavTPQZz38QzFTme79ENoN3Q==",
+      "funding": [
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/puzrin"
+        },
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/markdown-it"
+        }
+      ],
+      "license": "MIT",
+      "dependencies": {
+        "uc.micro": "^2.0.0"
+      }
+    },
     "node_modules/lru-cache": {
       "version": "6.0.0",
       "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-6.0.0.tgz",
@@ -574,6 +612,33 @@
         "node": ">=10"
       }
     },
+    "node_modules/markdown-it": {
+      "version": "14.3.0",
+      "resolved": "https://registry.npmjs.org/markdown-it/-/markdown-it-14.3.0.tgz",
+      "integrity": "sha512-RCEsPjR+sr0x+AuYp601tKTkgFG4YEPLCzHST3cQ/fhlJkqAkz1L2/Qbp1j9qw5SBwQHFBoW8+hoN5xssOF0Tw==",
+      "funding": [
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/puzrin"
+        },
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/markdown-it"
+        }
+      ],
+      "license": "MIT",
+      "dependencies": {
+        "argparse": "^2.0.1",
+        "entities": "^4.5.0",
+        "linkify-it": "^5.0.2",
+        "mdurl": "^2.0.0",
+        "punycode.js": "^2.3.1",
+        "uc.micro": "^2.1.0"
+      },
+      "bin": {
+        "markdown-it": "bin/markdown-it.mjs"
+      }
+    },
     "node_modules/math-intrinsics": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/math-intrinsics/-/math-intrinsics-1.1.0.tgz",
@@ -583,6 +648,12 @@
         "node": ">= 0.4"
       }
     },
+    "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/media-typer": {
       "version": "0.3.0",
       "resolved": "https://registry.npmjs.org/media-typer/-/media-typer-0.3.0.tgz",
@@ -898,6 +969,15 @@
         "node": ">= 0.10"
       }
     },
+    "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/qs": {
       "version": "6.15.2",
       "resolved": "https://registry.npmjs.org/qs/-/qs-6.15.2.tgz",
@@ -1135,6 +1215,12 @@
         "node": ">= 0.6"
       }
     },
+    "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/uid-safe": {
       "version": "2.1.5",
       "resolved": "https://registry.npmjs.org/uid-safe/-/uid-safe-2.1.5.tgz",