feat(athena): harden council config — mandatory name, guard prompt, no-crash duplicates

- Add council config guard prompt: when Athena has no valid council members,
  inject a STOP instruction telling the user how to configure council members
  instead of failing messily with generic agents
- Make council member 'name' field mandatory (was optional with auto-naming)
- Remove humanizeModelId and UPPERCASE_TOKENS — no more fragile auto-naming
- Replace throw on duplicate names with log + skip (graceful degradation)
- Update schema, types, tests (87 pass), and documentation

assets/oh-my-opencode.schema.json

@@ -5145,6 +5145,18 @@
             "providerOptions": {
               "type": "object",
               "additionalProperties": {}
+            },
+            "ultrawork": {
+              "type": "object",
+              "properties": {
+                "model": {
+                  "type": "string"
+                },
+                "variant": {
+                  "type": "string"
+                }
+              },
+              "additionalProperties": false
             }
           },
           "additionalProperties": false
@@ -5210,6 +5222,18 @@
               "type": "object",
               "additionalProperties": {}
             },
+            "ultrawork": {
+              "type": "object",
+              "properties": {
+                "model": {
+                  "type": "string"
+                },
+                "variant": {
+                  "type": "string"
+                }
+              },
+              "additionalProperties": false
+            },
             "council": {
               "type": "object",
               "properties": {
@@ -5227,7 +5251,8 @@
                         "type": "string"
                       },
                       "name": {
-                        "type": "string"
+                        "type": "string",
+                        "minLength": 1
                       },
                       "temperature": {
                         "type": "number",
@@ -5236,7 +5261,8 @@
                       }
                     },
                     "required": [
-                      "model"
+                      "model",
+                      "name"
                     ],
                     "additionalProperties": false
                   }