gitea: let an agent put a commit on a branch of its own, and read history, compares, reviews, directories and code (issue 375)

An agent could not get a finished change onto the forge without someone
pushing by hand, so the branch / pull request / approval rule could not be
followed. A Go bundle serves gitea_commit, held to gitea_api's rule (never the
default branch, never a protected one), and the summarised reads agents
otherwise made through gitea_api as raw JSON.

modules/gitea/module.json

@@ -257,6 +257,22 @@
           "MESH_GITEA_ADMIN_PASSWORD_FILE": "${dir:state}/admin.secret",
           "MESH_NPM_OWNER": "novox"
         }
+      },
+      {
+        "name": "forge",
+        "kind": "bundle",
+        "language": "go",
+        "system": "arch",
+        "from": "cmd/forge",
+        "binary": "forge",
+        "loads": [
+          "forge"
+        ],
+        "env": {
+          "MESH_GITEA_URL": "http://127.0.0.1:${port:3000}",
+          "MESH_GITEA_ADMIN_USER": "mesh-admin",
+          "MESH_GITEA_ADMIN_PASSWORD_FILE": "${dir:state}/admin.secret"
+        }
       }
     ]
   },