chore(release): carry 0.3.0-develop pre-release version between releases

package.json now holds a -develop pre-release suffix so the version
reported in the footer/health/stats distinguishes a dev build from a
shipped one (0.3.0-develop sorts below 0.3.0 per SemVer). Document the
release flow in CONTRIBUTING.md: strip the suffix at tag time, re-bump
to the next -develop afterward.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

CONTRIBUTING.md

@@ -72,6 +72,25 @@ docs(readme): add Continuous deployment section
 
 Common types: `feat`, `fix`, `refactor`, `docs`, `test`, `chore`.
 
+## Releasing
+
+The running version is read from `package.json` `version` and inlined at build
+time (footer, `/health`, `/api/v1/stats`). Between releases the working tree
+carries a `-develop` pre-release suffix so a dev build is never mistaken for a
+shipped one — `0.3.0-develop` sorts _below_ `0.3.0` per SemVer, meaning "heading
+toward 0.3.0, not yet released".
+
+To cut a release `X.Y.Z`:
+
+```bash
+npm version X.Y.Z --no-git-tag-version   # drop the -develop suffix
+# commit, tag vX.Y.Z, push, deploy (npm run deploy)
+npm version X.Y+1.0-develop --no-git-tag-version   # reopen the next cycle
+```
+
+So `main` should always read `*-develop`; only a tagged release commit carries a
+bare `X.Y.Z`.
+
 ## Reporting bugs and requesting features
 
 Open an issue at

package.json

@@ -1,6 +1,6 @@
 {
   "name": "kill-the-news",
-  "version": "0.2.1",
+  "version": "0.3.0-develop",
   "description": "Convert email newsletters into private RSS feeds using Cloudflare Workers",
   "main": "dist/worker.js",
   "scripts": {