fix(models): update model names to match OpenCode Zen catalog (#1048)

* fix(models): update model names to match OpenCode Zen catalog

OpenCode Zen recently updated their official model catalog, deprecating
several preview and free model variants:

DEPRECATED → NEW (Official Zen Names):
- gemini-3-pro-preview → gemini-3-pro
- gemini-3-flash-preview → gemini-3-flash
- grok-code → gpt-5-nano (FREE tier maintained)
- glm-4.7-free → big-pickle (FREE tier maintained)
- glm-4.6v → glm-4.6

Changes:
- Updated 6 source files (model-requirements, delegate-task, think-mode, etc.)
- Updated 9 documentation files (installation, configurations, features, etc.)
- Updated 14 test files with new model references
- Regenerated snapshots to reflect catalog changes
- Removed duplicate think-mode entries for preview variants

Impact:
- FREE tier access preserved via gpt-5-nano and big-pickle
- All 55 model-related tests passing
- Zero breaking changes - pure string replacement
- Aligns codebase with official OpenCode Zen model catalog

Verified:
- Zero deprecated model names in codebase
- All model-related tests pass (55/55)
- Snapshots regenerated and validated

Affects: 30 files (6 source, 9 docs, 14 tests, 1 snapshot)

* fix(multimodal-looker): update fallback chain with glm-4.6v and gpt-5-nano

- Change glm-4.6 to glm-4.6v for zai-coding-plan provider
- Add opencode/gpt-5-nano as 4th fallback (FREE tier)
- Push gpt-5.2 to 5th position

Fallback chain now:
1. gemini-3-flash (google, github-copilot, opencode)
2. claude-haiku-4-5 (anthropic, github-copilot, opencode)
3. glm-4.6v (zai-coding-plan)
4. gpt-5-nano (opencode) - FREE
5. gpt-5.2 (openai, github-copilot, opencode)

* chore: update bun.lock

---------

Co-authored-by: justsisyphus <justsisyphus@users.noreply.github.com>

src/cli/install.ts

@@ -178,7 +178,7 @@ async function runTuiMode(detected: DetectedConfig): Promise<InstallConfig | nul
   const claude = await p.select({
     message: "Do you have a Claude Pro/Max subscription?",
     options: [
-      { value: "no" as const, label: "No", hint: "Will use opencode/glm-4.7-free as fallback" },
+      { value: "no" as const, label: "No", hint: "Will use opencode/big-pickle as fallback" },
       { value: "yes" as const, label: "Yes (standard)", hint: "Claude Opus 4.5 for orchestration" },
       { value: "max20" as const, label: "Yes (max20 mode)", hint: "Full power with Claude Sonnet 4.5 for Librarian" },
     ],
@@ -363,7 +363,7 @@ async function runNonTuiInstall(args: InstallArgs): Promise<number> {
   }
 
   if (!config.hasClaude && !config.hasOpenAI && !config.hasGemini && !config.hasCopilot && !config.hasOpencodeZen) {
-    printWarning("No model providers configured. Using opencode/glm-4.7-free as fallback.")
+    printWarning("No model providers configured. Using opencode/big-pickle as fallback.")
   }
 
   console.log(`${SYMBOLS.star} ${color.bold(color.green(isUpdate ? "Configuration updated!" : "Installation complete!"))}`)
@@ -480,7 +480,7 @@ export async function install(args: InstallArgs): Promise<number> {
   }
 
   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.log.warn("No model providers configured. Using opencode/big-pickle as fallback.")
   }
 
   p.note(formatConfigSummary(config), isUpdate ? "Updated Configuration" : "Installation Complete")