refactor(cli): split install.ts and model-fallback.ts into focused modules

Install pipeline:
- cli-installer.ts, tui-installer.ts, tui-install-prompts.ts
- install-validators.ts

Model fallback:
- model-fallback-types.ts, fallback-chain-resolution.ts
- provider-availability.ts, provider-model-id-transform.ts

src/cli/tui-installer.ts

@@ -0,0 +1,135 @@
+import * as p from "@clack/prompts"
+import color from "picocolors"
+import type { InstallArgs } from "./types"
+import {
+  addAuthPlugins,
+  addPluginToOpenCodeConfig,
+  addProviderConfig,
+  detectCurrentConfig,
+  getOpenCodeVersion,
+  isOpenCodeInstalled,
+  writeOmoConfig,
+} from "./config-manager"
+import { detectedToInitialValues, formatConfigSummary, SYMBOLS } from "./install-validators"
+import { promptInstallConfig } from "./tui-install-prompts"
+
+export async function runTuiInstaller(args: InstallArgs, version: string): Promise<number> {
+  const detected = detectCurrentConfig()
+  const isUpdate = detected.isInstalled
+
+  p.intro(color.bgMagenta(color.white(isUpdate ? " oMoMoMoMo... Update " : " oMoMoMoMo... ")))
+
+  if (isUpdate) {
+    const initial = detectedToInitialValues(detected)
+    p.log.info(`Existing configuration detected: Claude=${initial.claude}, Gemini=${initial.gemini}`)
+  }
+
+  const spinner = p.spinner()
+  spinner.start("Checking OpenCode installation")
+
+  const installed = await isOpenCodeInstalled()
+  const openCodeVersion = await getOpenCodeVersion()
+  if (!installed) {
+    spinner.stop(`OpenCode binary not found ${color.yellow("[!]")}`)
+    p.log.warn("OpenCode binary not found. Plugin will be configured, but you'll need to install OpenCode to use it.")
+    p.note("Visit https://opencode.ai/docs for installation instructions", "Installation Guide")
+  } else {
+    spinner.stop(`OpenCode ${openCodeVersion ?? "installed"} ${color.green("[OK]")}`)
+  }
+
+  const config = await promptInstallConfig(detected)
+  if (!config) return 1
+
+  spinner.start("Adding oh-my-opencode to OpenCode config")
+  const pluginResult = await addPluginToOpenCodeConfig(version)
+  if (!pluginResult.success) {
+    spinner.stop(`Failed to add plugin: ${pluginResult.error}`)
+    p.outro(color.red("Installation failed."))
+    return 1
+  }
+  spinner.stop(`Plugin added to ${color.cyan(pluginResult.configPath)}`)
+
+  if (config.hasGemini) {
+    spinner.start("Adding auth plugins (fetching latest versions)")
+    const authResult = await addAuthPlugins(config)
+    if (!authResult.success) {
+      spinner.stop(`Failed to add auth plugins: ${authResult.error}`)
+      p.outro(color.red("Installation failed."))
+      return 1
+    }
+    spinner.stop(`Auth plugins added to ${color.cyan(authResult.configPath)}`)
+
+    spinner.start("Adding provider configurations")
+    const providerResult = addProviderConfig(config)
+    if (!providerResult.success) {
+      spinner.stop(`Failed to add provider config: ${providerResult.error}`)
+      p.outro(color.red("Installation failed."))
+      return 1
+    }
+    spinner.stop(`Provider config added to ${color.cyan(providerResult.configPath)}`)
+  }
+
+  spinner.start("Writing oh-my-opencode configuration")
+  const omoResult = writeOmoConfig(config)
+  if (!omoResult.success) {
+    spinner.stop(`Failed to write config: ${omoResult.error}`)
+    p.outro(color.red("Installation failed."))
+    return 1
+  }
+  spinner.stop(`Config written to ${color.cyan(omoResult.configPath)}`)
+
+  if (!config.hasClaude) {
+    console.log()
+    console.log(color.bgRed(color.white(color.bold(" CRITICAL WARNING "))))
+    console.log()
+    console.log(color.red(color.bold("  Sisyphus agent is STRONGLY optimized for Claude Opus 4.5.")))
+    console.log(color.red("  Without Claude, you may experience significantly degraded performance:"))
+    console.log(color.dim("    • Reduced orchestration quality"))
+    console.log(color.dim("    • Weaker tool selection and delegation"))
+    console.log(color.dim("    • Less reliable task completion"))
+    console.log()
+    console.log(color.yellow("  Consider subscribing to Claude Pro/Max for the best experience."))
+    console.log()
+  }
+
+  if (!config.hasClaude && !config.hasOpenAI && !config.hasGemini && !config.hasCopilot && !config.hasOpencodeZen) {
+    p.log.warn("No model providers configured. Using opencode/glm-4.7-free as fallback.")
+  }
+
+  p.note(formatConfigSummary(config), isUpdate ? "Updated Configuration" : "Installation Complete")
+
+  p.log.success(color.bold(isUpdate ? "Configuration updated!" : "Installation complete!"))
+  p.log.message(`Run ${color.cyan("opencode")} to start!`)
+
+  p.note(
+    `Include ${color.cyan("ultrawork")} (or ${color.cyan("ulw")}) in your prompt.\n` +
+      `All features work like magic—parallel agents, background tasks,\n` +
+      `deep exploration, and relentless execution until completion.`,
+    "The Magic Word",
+  )
+
+  p.log.message(`${color.yellow("★")} If you found this helpful, consider starring the repo!`)
+  p.log.message(
+    `  ${color.dim("gh api --silent --method PUT /user/starred/code-yeongyu/oh-my-opencode >/dev/null 2>&1 || true")}`,
+  )
+
+  p.outro(color.green("oMoMoMoMo... Enjoy!"))
+
+  if ((config.hasClaude || config.hasGemini || config.hasCopilot) && !args.skipAuth) {
+    const providers: string[] = []
+    if (config.hasClaude) providers.push(`Anthropic ${color.gray("→ Claude Pro/Max")}`)
+    if (config.hasGemini) providers.push(`Google ${color.gray("→ OAuth with Antigravity")}`)
+    if (config.hasCopilot) providers.push(`GitHub ${color.gray("→ Copilot")}`)
+
+    console.log()
+    console.log(color.bold("Authenticate Your Providers"))
+    console.log()
+    console.log(`   Run ${color.cyan("opencode auth login")} and select:`)
+    for (const provider of providers) {
+      console.log(`   ${SYMBOLS.bullet} ${provider}`)
+    }
+    console.log()
+  }
+
+  return 0
+}