SEV-329: @switchev/web-shared package — formatters, markdown, waitForImage

Stands up the shared browser-helpers package (consumed by public/vendor/admin
via the Gitea npm registry) to de-duplicate copy-pasted frontend code:
- format.js: formatLabel/formatStatus/formatTimeline/formatBudget (single source
  of truth — these had drifted, see SEV-310).
- markdown.js: renderMarkdown (marked + strict DOMPurify; both peer deps).
- wait-image.js: waitForImage (was byte-identical in public + vendor).

ESM source package (no build step — Vite consumers import directly). publishConfig
points at the Gitea npm registry. node --test green (formatters).

Next: publish v0.1.0, then migrate each site to consume it and delete the copies.

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

package.json

@@ -1,8 +1,32 @@
 {
-  "name": "switchev-shared",
+  "name": "@switchev/web-shared",
   "version": "0.1.0",
-  "private": true,
-  "description": "Shared constants, validation schemas, and type definitions for SwitchEV",
+  "description": "Shared browser helpers (formatters, markdown, image polling) for the SwitchEV frontends",
   "type": "module",
-  "main": "index.js"
+  "exports": {
+    ".": "./src/index.js",
+    "./format": "./src/format.js",
+    "./markdown": "./src/markdown.js",
+    "./wait-image": "./src/wait-image.js"
+  },
+  "files": [
+    "src"
+  ],
+  "sideEffects": [
+    "./src/markdown.js"
+  ],
+  "peerDependencies": {
+    "dompurify": ">=3",
+    "marked": ">=12"
+  },
+  "scripts": {
+    "test": "node --test"
+  },
+  "publishConfig": {
+    "registry": "https://git.debyl.io/api/packages/SwitchEV/npm/"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://git.debyl.io/SwitchEV/shared.git"
+  }
 }