fix: make the Trust Manifest MUST rules satisfiable by the spec's own examples

specification/ai-catalog.md

@@ -406,12 +406,17 @@ A Trust Manifest MUST contain:
   DID, SPIFFE ID, or URL; these are illustrative and the set of
   identity schemes is open.
 
-When a Trust Manifest appears within a Catalog Entry, the `identity`
-field's authority or trust domain MUST align with the publisher domain segment of
-the entry's URN `identifier` field. This binding ensures trust claims are
-cryptographically bound to the authorized publisher of the catalog entry.
-Consumers MUST reject a Trust Manifest whose identity domain does not
-align with the publisher domain of the entry's `identifier`.
+When a Trust Manifest appears within a Catalog Entry whose
+`identifier` carries a publisher domain segment (such as the
+`urn:air` naming format), the `identity` field's authority or trust
+domain MUST align with that publisher domain. This binding ensures
+trust claims are bound to the authorized publisher of the catalog
+entry. Consumers MUST reject a Trust Manifest whose identity domain
+does not align with the publisher domain of such an entry's
+`identifier`. When the `identifier` format has no publisher domain
+segment (custom or local formats), this check does not apply, and
+consumers SHOULD rely on other verification instead, such as
+attestations or signature verification.
 
 When a Trust Manifest appears on a Host Info object, `identity`
 SHOULD match the host's `identifier` field when present.
@@ -1977,7 +1982,7 @@ plugins/
 | Plugin `tags` | Entry `tags[]` (merged with category) |
 | Plugin `author` | Entry `publisher` |
 | Plugin `source` (url, git-subdir, or path) | Entry `url` (pointing to the plugin repository) |
-| Plugin `source.sha` | Entry `trustManifest.provenance[].sourceDigest` |
+| Plugin `source.sha` | Entry `metadata.sourceSha` (a git revision identifier, not a content digest) |
 | Plugin `homepage` | Entry `metadata.homepage` |
 | Plugin `.claude-plugin/plugin.json` | The artifact content (referenced via `url`) |
 | *(not in marketplace)* | Entry `trustManifest` (identity, attestations) |
@@ -1992,7 +1997,10 @@ differently to AI Catalog entry fields:
 Direct URL source
 : `{"source": "url", "url": "https://github.com/org/repo.git", "sha": "..."}`
   maps to entry `url` pointing at the repository, with `sha` captured
-  as provenance digest.
+  in entry `metadata`. A git commit SHA is a revision identifier
+  rather than a content digest of a fetchable document, so it does not
+  map to `sourceDigest` (which also requires SHA-256 or stronger, see
+  [Digest Format](#digest-format)).
 
 Git subdirectory source
 : `{"source": "git-subdir", "url": "org/repo", "path": "plugins/name", "ref": "main"}`
@@ -2038,15 +2046,15 @@ maps to an AI Catalog where each plugin is an entry:
       "description": "Cross-platform ad management for Google Ads, Meta Ads, TikTok Ads, and LinkedIn Ads.",
       "tags": ["productivity", "ads"],
       "metadata": {
-        "homepage": "https://www.adspirer.com"
+        "homepage": "https://www.adspirer.com",
+        "sourceSha": "aa70dbdbbbb843e94a794c10c2b13f5dd66b5e40"
       },
       "trustManifest": {
         "identity": "urn:claude-plugin:adspirer:ads-agent",
         "provenance": [
           {
             "relation": "publishedFrom",
-            "sourceId": "https://github.com/amekala/adspirer-mcp-plugin",
-            "sourceDigest": "sha1:aa70dbdbbbb843e94a794c10c2b13f5dd66b5e40"
+            "sourceId": "https://github.com/amekala/adspirer-mcp-plugin"
           }
         ]
       }
@@ -2061,13 +2069,15 @@ maps to an AI Catalog where each plugin is an entry:
         "identifier": "did:web:aikido.dev",
         "displayName": "Aikido Security"
       },
+      "metadata": {
+        "sourceSha": "d7fa8b8e192680d9a26c1a5dcaead7cf5cdb7139"
+      },
       "trustManifest": {
         "identity": "urn:claude-plugin:aikido:security",
         "provenance": [
           {
             "relation": "publishedFrom",
-            "sourceId": "https://github.com/AikidoSec/aikido-claude-plugin",
-            "sourceDigest": "sha1:d7fa8b8e192680d9a26c1a5dcaead7cf5cdb7139"
+            "sourceId": "https://github.com/AikidoSec/aikido-claude-plugin"
           }
         ]
       }