fix(config): preserve explicit git_master overrides during merge

Prevent project config defaults from re-enabling git_master fields that users explicitly disabled. Rebuild git_master from explicit user and project keys so include_co_authored_by and commit_footer merge predictably.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/plugin-config.ts

@@ -13,6 +13,26 @@ import {
 import { migrateLegacyConfigFile } from "./shared/migrate-legacy-config-file";
 import { CONFIG_BASENAME, LEGACY_CONFIG_BASENAME } from "./shared/plugin-identity";
 
+function loadExplicitGitMasterOverrides(configPath: string): Record<string, unknown> | undefined {
+  try {
+    if (!fs.existsSync(configPath)) {
+      return undefined
+    }
+
+    const content = fs.readFileSync(configPath, "utf-8")
+    const rawConfig = parseJsonc<Record<string, unknown>>(content)
+    const gitMaster = rawConfig.git_master
+
+    if (gitMaster && typeof gitMaster === "object" && !Array.isArray(gitMaster)) {
+      return gitMaster as Record<string, unknown>
+    }
+  } catch {
+    return undefined
+  }
+
+  return undefined
+}
+
 const PARTIAL_STRING_ARRAY_KEYS = new Set([
   "disabled_mcps",
   "disabled_agents",
@@ -229,15 +249,29 @@ export function loadPluginConfig(
 
   // Load user config first (base). Parse empty config through Zod to apply field defaults.
   const userConfig = loadConfigFromPath(userConfigPath, ctx)
+  const userGitMasterOverrides = loadExplicitGitMasterOverrides(userConfigPath)
   let config: OhMyOpenCodeConfig =
     userConfig ?? OhMyOpenCodeConfigSchema.parse({});
 
   // Override with project config
+  const defaultGitMaster = OhMyOpenCodeConfigSchema.parse({}).git_master
   const projectConfig = loadConfigFromPath(projectConfigPath, ctx);
+  const projectGitMasterOverrides = loadExplicitGitMasterOverrides(projectConfigPath)
   if (projectConfig) {
     config = mergeConfigs(config, projectConfig);
   }
 
+  if (userGitMasterOverrides || projectGitMasterOverrides) {
+    config = {
+      ...config,
+      git_master: {
+        ...defaultGitMaster,
+        ...(userGitMasterOverrides ?? {}),
+        ...(projectGitMasterOverrides ?? {}),
+      },
+    }
+  }
+
   config = {
     ...config,
     mcp_env_allowlist: userConfig?.mcp_env_allowlist ?? [],