refactor: rename OhMyOpenCode types to OhMyOpenAgent and centralize PACKAGE_NAME

- Rename all PascalCase types: OhMyOpenCodePlugin → OhMyOpenAgentPlugin, etc.
- 231 OhMyOpenAgent references across ~60 files
- Centralize 4 PACKAGE_NAME constants to import from plugin-identity.ts
- Update src/plugin-config.ts to use CONFIG_BASENAME from plugin-identity

Wave 3 Tasks 5 & 6 complete.

src/plugin/hooks/create-continuation-hooks.ts

@@ -1,4 +1,4 @@
-import type { HookName, OhMyOpenCodeConfig } from "../../config"
+import type { HookName, OhMyOpenAgentConfig } from "../../config"
 import type { BackgroundManager } from "../../features/background-agent"
 import type { PluginContext } from "../types"
 
@@ -32,7 +32,7 @@ type SessionRecovery = {
 
 export function createContinuationHooks(args: {
   ctx: PluginContext
-  pluginConfig: OhMyOpenCodeConfig
+  pluginConfig: OhMyOpenAgentConfig
   isHookEnabled: (hookName: HookName) => boolean
   safeHookEnabled: boolean
   backgroundManager: BackgroundManager