build: retire the old TypeDoc theme and its assets

Phase E of #81. `typedoc-unhoax-theme` has been unreferenced since the API
reference moved to markdown, and the two theme assets it loaded are dead weight
in the published package.

- `typedoc-unhoax-theme` is out of `devDependencies`; `npm ci` still installs the
  committed lockfile, and the package is gone from `node_modules`.
- `assets/custom.css` and `assets/custom.js` are deleted, and out of the `files`
  allowlist with them: measured `npm pack` goes from 30 files / 67kB to
  **28 files / 66.6kB**, with `assets/favicon.ico` as the only asset left.
- `AGENTS.md` and `docs/contributor/compatibility.md` carry the new allowlist and
  the measured counts.
- `gh-pages` stays for now: `doc:publish` is the fallback deployment path until
  the repository's Pages source is switched to GitHub Actions, and the ledger
  records that as the one remaining step.

Verified after the change: `npm ci --include=dev` against the committed lockfile,
lint 0/0, format:check, typecheck (TS 7), verify:docs, docs:build (11 legacy
redirects written), 126 tests passed / 2 skipped, coverage 100%, verify:package
green (bundler, node16, nodenext, and the three documentation examples).

Author: soimy

AGENTS.md

@@ -334,15 +334,15 @@ English keeps the project history usable for every contributor and every downstr
   There is still no `exports` field, so deep imports (`maxrects-packer/dist/...`) work; adding one
   would seal off deep paths, which is breaking and therefore reserved for 3.0.0.
 - Published content is decided by the `files` allowlist in `package.json`: `dist` + `src` +
-  `assets/{custom.css,custom.js,favicon.ico}` + `CHANGELOG.md` + `tsconfig*.json` + `typedoc.json`
-  (measured `npm pack`: ~62kB / 30 files — the byte count drifts slightly between builds, the file
+  `assets/favicon.ico` + `CHANGELOG.md` + `tsconfig*.json` + `typedoc.json`
+  (measured `npm pack`: ~66kB / 28 files — the byte count drifts slightly between builds, the file
   count does not; the published 2.7.4 tarball was 67.0kB / 33 files). The differences from 2.7.4 are
   all deliberate: `eslint.config.js`, `.eslintrc.json` and `.github/workflows/node.js.yml` are no
   longer published, `dist/maxrects-packer.cjs` is new, and `UPGRADE_SUMMARY.md` was deleted as an
   obsolete dependency-upgrade log. There is **no `.npmignore`**, so npm falls back to `.gitignore`
   (which lists `dist`/`lib`), but `files` wins and `dist` still ships. Note that `assets/*.png` is not
   in the allowlist (2.7.x did not ship it either), so the README images stay broken on the npm page;
-  adding the whole `assets` directory would fix that at the cost of growing the tarball from ~62kB to
+  adding the whole `assets` directory would fix that at the cost of growing the tarball from ~66kB to
   ~530kB (`assets/` is 468kB, mostly uncompressed PNG). `clean` removes both `dist` and the legacy
   `lib`.
 - The `resolved` fields in `package-lock.json` must point at `registry.npmjs.org`: this machine has a

assets/custom.css

@@ -53,8 +53,8 @@ fixture compiled with `bundler`, `node16` and `nodenext`.
 
 ## What ships
 
-The `files` allowlist decides: `dist`, `src`, `assets/{custom.css,custom.js,favicon.ico}`,
-`CHANGELOG.md`, `tsconfig*.json` and `typedoc.json` — currently 30 files. `docs/`, the documentation
+The `files` allowlist decides: `dist`, `src`, `assets/favicon.ico`, `CHANGELOG.md`, `tsconfig*.json`
+and `typedoc.json` — currently 28 files. `docs/`, the documentation
 site and internal plans are not in it and never ship.
 
 ## Node version

assets/custom.js

@@ -55,5 +55,11 @@ the old TypeDoc site published. Switching the repository's Pages source to **Git
 maintainer step that has to happen before the first deployment; until then `doc:publish` still pushes to
 `gh-pages`, and the two paths must not be used together.
 
-Still open: retiring the old theme, `gh-pages` and the theme assets from `devDependencies` and the
-`files` allowlist. The published tarball is unaffected: `docs/` is not in the `files` allowlist.
+The old theme is retired: `typedoc-unhoax-theme`, `assets/custom.css` and `assets/custom.js` are gone
+from `devDependencies`, the repository and the `files` allowlist, which takes the published tarball from
+30 files to 28 (`assets/favicon.ico` stays).
+
+Still open: dropping `gh-pages` (and the `doc:publish` alias that uses it) once the Pages source is
+switched to GitHub Actions — until then it is the fallback deployment path. `cz-conventional-changelog`
+is unrelated stale tooling (interactive commitizen commits only). The published tarball is otherwise
+unaffected: `docs/` is not in the `files` allowlist.

docs/contributor/compatibility.md

@@ -9,8 +9,6 @@
   "files": [
     "dist",
     "src",
-    "assets/custom.css",
-    "assets/custom.js",
     "assets/favicon.ico",
     "CHANGELOG.md",
     "tsconfig.json",
@@ -79,7 +77,6 @@
     "tslib": "^2.8.1",
     "typedoc": "^0.28.20",
     "typedoc-plugin-markdown": "^4.13.1",
-    "typedoc-unhoax-theme": "^0.5.3",
     "typedoc-vitepress-theme": "^1.1.4",
     "typescript": "npm:@typescript/typescript6@^6.0.2",
     "vitepress": "^1.6.4",