chore: replace hand-rolled layout() with @fastify/view + EJS

Convert all src/views/*.ts template-literal modules to .ejs templates
under views/. Register @fastify/view plugin in server.ts with EJS
engine and _layout.ejs as the layout file. Update route handlers to
use reply.view() instead of reply.send(layout(...)). Delete the old
TypeScript view modules and layout.ts.

Closes #19

package-lock.json

@@ -15,15 +15,18 @@
         "@fastify/multipart": "^9.4.0",
         "@fastify/rate-limit": "^10.3.0",
         "@fastify/static": "^9.0.0",
+        "@fastify/view": "^11.1.1",
         "bchen-sqlite-migrate": "git+https://gitea.bchen.dev/brendan/sqlite-migrate.git#v0.1.0",
         "bcrypt": "^6.0.0",
         "better-sqlite3": "^12.6.2",
+        "ejs": "^5.0.2",
         "fastify": "^5.7.4",
         "nanoid": "^5.1.6"
       },
       "devDependencies": {
         "@types/bcrypt": "^6.0.0",
         "@types/better-sqlite3": "^7.6.13",
+        "@types/ejs": "^3.1.5",
         "@types/node": "^25.3.3",
         "tsx": "^4.21.0",
         "typescript": "^5.9.3",
@@ -809,6 +812,26 @@
         "glob": "^13.0.0"
       }
     },
+    "node_modules/@fastify/view": {
+      "version": "11.1.1",
+      "resolved": "https://registry.npmjs.org/@fastify/view/-/view-11.1.1.tgz",
+      "integrity": "sha512-GiHqT3R2eKJgWmy0s45eELTC447a4+lTM2o+8fSWeKwBe9VToeePuHJcKtOEXPrKGSddGO0RsNayULiS3aeHeQ==",
+      "funding": [
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/fastify"
+        },
+        {
+          "type": "opencollective",
+          "url": "https://opencollective.com/fastify"
+        }
+      ],
+      "license": "MIT",
+      "dependencies": {
+        "fastify-plugin": "^5.0.0",
+        "toad-cache": "^3.7.0"
+      }
+    },
     "node_modules/@jridgewell/sourcemap-codec": {
       "version": "1.5.5",
       "resolved": "https://registry.npmjs.org/@jridgewell/sourcemap-codec/-/sourcemap-codec-1.5.5.tgz",
@@ -1198,6 +1221,13 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/@types/ejs": {
+      "version": "3.1.5",
+      "resolved": "https://registry.npmjs.org/@types/ejs/-/ejs-3.1.5.tgz",
+      "integrity": "sha512-nv+GSx77ZtXiJzwKdsASqi+YQ5Z7vwHsTP0JY2SiQgjGckkBRKZnk8nIM+7oUZ1VCtuTz0+By4qVR7fqzp/Dfg==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/@types/estree": {
       "version": "1.0.9",
       "resolved": "https://registry.npmjs.org/@types/estree/-/estree-1.0.9.tgz",
@@ -1657,6 +1687,18 @@
         "safe-buffer": "^5.0.1"
       }
     },
+    "node_modules/ejs": {
+      "version": "5.0.2",
+      "resolved": "https://registry.npmjs.org/ejs/-/ejs-5.0.2.tgz",
+      "integrity": "sha512-IpbUaI/CAW86l3f+T8zN0iggSc0LmMZLcIW5eRVStLVNCoTXkE0YlncbbH50fp8Cl6zHIky0sW2uUbhBqGw0Jw==",
+      "license": "Apache-2.0",
+      "bin": {
+        "ejs": "bin/cli.js"
+      },
+      "engines": {
+        "node": ">=0.12.18"
+      }
+    },
     "node_modules/end-of-stream": {
       "version": "1.4.5",
       "resolved": "https://registry.npmjs.org/end-of-stream/-/end-of-stream-1.4.5.tgz",