feat(compat): package rename compatibility layer for oh-my-opencode → oh-my-openagent

- Add legacy plugin startup warning when oh-my-opencode config detected
- Update CLI installer and TUI installer for new package name
- Split monolithic config-manager.test.ts into focused test modules
- Add plugin config detection tests for legacy name fallback
- Update processed-command-store to use plugin-identity constants
- Add claude-code-plugin-loader discovery test for both config names
- Update chat-params and ultrawork-db tests for plugin identity

Part of #2823

src/shared/log-legacy-plugin-startup-warning.test.ts

@@ -0,0 +1,76 @@
+import { beforeEach, describe, expect, it, mock } from "bun:test"
+import type { LegacyPluginCheckResult } from "./legacy-plugin-warning"
+
+function createLegacyPluginCheckResult(
+  overrides: Partial<LegacyPluginCheckResult> = {},
+): LegacyPluginCheckResult {
+  return {
+    hasLegacyEntry: false,
+    hasCanonicalEntry: false,
+    legacyEntries: [],
+    ...overrides,
+  }
+}
+
+const mockCheckForLegacyPluginEntry = mock(() => createLegacyPluginCheckResult())
+
+const mockLog = mock(() => {})
+
+mock.module("./legacy-plugin-warning", () => ({
+  checkForLegacyPluginEntry: mockCheckForLegacyPluginEntry,
+}))
+
+mock.module("./logger", () => ({
+  log: mockLog,
+}))
+
+async function importFreshStartupWarningModule(): Promise<typeof import("./log-legacy-plugin-startup-warning")> {
+  return import(`./log-legacy-plugin-startup-warning?test=${Date.now()}-${Math.random()}`)
+}
+
+describe("logLegacyPluginStartupWarning", () => {
+  beforeEach(() => {
+    mockCheckForLegacyPluginEntry.mockReset()
+    mockLog.mockReset()
+
+    mockCheckForLegacyPluginEntry.mockReturnValue(createLegacyPluginCheckResult())
+  })
+
+  describe("#given OpenCode config contains legacy plugin entries", () => {
+    it("logs the legacy entries with canonical replacements", async () => {
+      //#given
+      mockCheckForLegacyPluginEntry.mockReturnValue(createLegacyPluginCheckResult({
+        hasLegacyEntry: true,
+        legacyEntries: ["oh-my-opencode", "oh-my-opencode@3.13.1"],
+      }))
+      const { logLegacyPluginStartupWarning } = await importFreshStartupWarningModule()
+
+      //#when
+      logLegacyPluginStartupWarning()
+
+      //#then
+      expect(mockLog).toHaveBeenCalledTimes(1)
+      expect(mockLog).toHaveBeenCalledWith(
+        "[OhMyOpenCodePlugin] Legacy plugin entry detected in OpenCode config",
+        {
+          legacyEntries: ["oh-my-opencode", "oh-my-opencode@3.13.1"],
+          suggestedEntries: ["oh-my-openagent", "oh-my-openagent@3.13.1"],
+          hasCanonicalEntry: false,
+        },
+      )
+    })
+  })
+
+  describe("#given OpenCode config uses only canonical plugin entries", () => {
+    it("does not log a startup warning", async () => {
+      //#given
+      const { logLegacyPluginStartupWarning } = await importFreshStartupWarningModule()
+
+      //#when
+      logLegacyPluginStartupWarning()
+
+      //#then
+      expect(mockLog).not.toHaveBeenCalled()
+    })
+  })
+})