enhance(packages/npm): expand version metadata and support npm deprecate (#37890)

Fixes #21624

Adds the npm package version metadata fields that Gitea's npm registry
was previously dropping on publish, and implements the `npm deprecate`
command, which Gitea did not accept before.

### New / pass-through metadata fields

The following are now parsed from the publish payload, persisted in the
stored `npm.Metadata`, and re-emitted on the abbreviated version
manifest returned to npm clients:

- `hasInstallScript` — auto-detected from `scripts.preinstall` /
`scripts.install` / `scripts.postinstall` (also honors a client-supplied
value). Without this flag, `npm install` skips lifecycle scripts.
- `_hasShrinkwrap` — authoritatively derived by inspecting the uploaded
tarball for a top-level `*/npm-shrinkwrap.json` entry. Client-supplied
values are ignored. Decompression failures fall back to `false` and do
not block publish (integrity has already been validated).
- `engines` (`map[string]string`)
- `cpu`, `os` (`[]string`)
- `directories` (`map[string]string`)
- `funding` (`any`; preserves the spec's string / object / array shape)
- `acceptDependencies` (`map[string]string`)
- `deprecated` (`string`)

`peerDependenciesMeta` was already in the stored struct but is now
exercised
by tests.

### `npm deprecate` support

`npm deprecate <pkg-spec> <message>` PUTs the package document to the
same URL as publish but with no `_attachments`. The router now detects
that shape and routes to a new handler that updates each affected
version's stored `Metadata.Deprecated` via
`packages_model.UpdateVersion`. An empty message clears the flag
(undeprecate). Unknown versions are silently skipped, matching npm's
behavior. No new routes were added.

Supported invocations include:

- `npm deprecate my-thing@"< 0.2.3" "critical bug fixed in v0.2.3"`
- `npm deprecate my-thing@1.x "1.x is no longer supported"`
- `npm deprecate my-thing@1.0.0 ""` (undeprecate)

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: bircni <bircni@icloud.com>

routers/api/packages/npm/api.go

@@ -71,6 +71,15 @@ func createPackageMetadataVersion(registryURL string, pd *packages_model.Package
 		OptionalDependencies: metadata.OptionalDependencies,
 		Readme:               metadata.Readme,
 		Bin:                  metadata.Bin,
+		HasInstallScript:     metadata.HasInstallScript,
+		HasShrinkwrap:        metadata.HasShrinkwrap,
+		Engines:              metadata.Engines,
+		CPU:                  metadata.CPU,
+		OS:                   metadata.OS,
+		Directories:          metadata.Directories,
+		Funding:              metadata.Funding,
+		AcceptDependencies:   metadata.AcceptDependencies,
+		Deprecated:           metadata.Deprecated,
 		Dist: npm_module.PackageDistribution{
 			Shasum:    pd.Files[0].Blob.HashSHA1,
 			Integrity: "sha512-" + base64.StdEncoding.EncodeToString(hashBytes),