✨ Add pubv-based release.sh and npm run release

Release front-door: pubv runs preflight + the interactive semver
heuristic and graduates CHANGELOG.md [Unreleased] -> dated; npm version
syncs package.json + lockfile; git commit --amend folds them into
pubv's single release commit; the tag is created AFTER the amend so it
marks the exact commit on main that gets published; then push. Tags are
v-less (--tag-prefix=none) to match the changelog compare refs.

@runwisp/pubv added as a devDependency. The short "how we got here /
what was rejected" note lives as a comment atop the script; the docs/
exploration was removed as too much to read.

package-lock.json

@@ -10,6 +10,7 @@
             "license": "MIT",
             "devDependencies": {
                 "@arethetypeswrong/cli": "^0.18.5",
+                "@runwisp/pubv": "^1.5.1",
                 "@tsconfig/node26": "^26.0.1",
                 "@tsconfig/strictest": "^2.0.8",
                 "@types/node": "^26.4.1",
@@ -2299,6 +2300,22 @@
                 "url": "https://bjornlu.com/sponsor"
             }
         },
+        "node_modules/@runwisp/pubv": {
+            "version": "1.5.1",
+            "resolved": "https://registry.npmjs.org/@runwisp/pubv/-/pubv-1.5.1.tgz",
+            "integrity": "sha512-8Tf90OQRJRmRIOXi8Bb0EzRa2rCbi48PG+ISZUTaNpHRrLOy45v8+SpQnigs0Ot6B/9wzseU8AX1Kukg+i+f2A==",
+            "dev": true,
+            "license": "MIT",
+            "dependencies": {
+                "picocolors": "^1.1.1"
+            },
+            "bin": {
+                "pubv": "dist/bin.js"
+            },
+            "engines": {
+                "node": ">=20"
+            }
+        },
         "node_modules/@sindresorhus/is": {
             "version": "4.6.0",
             "resolved": "https://registry.npmjs.org/@sindresorhus/is/-/is-4.6.0.tgz",