fix(git): fix 17 missing async/await bugs + UX overhaul

Backend:
- fix 17 missing 'await' in git route handlers causing silent no-ops
  (branches, diff, history, commit, push, pull, merge, promote, sync)
- fix async coroutine passed to run_blocking in git_plugin.py

Frontend:
- add collapsible 'How it works' onboarding (GitHelpPanel)
- add status legend with color-coded repository statuses
- i18n: add 50+ missing keys, replace hardcoded strings
- add Refresh button in modal header
- add PROD deploy confirmation dialog (replaces browser prompt())
- add CommitHistory to workspace tab with timeline nodes
- add post-commit success banner with next-step guidance
- increase success toast duration to 8s
- group local/remote branches in selector (optgroup)
- format last_modified dates timezone-aware
- change PROD badge from red to neutral indigo
- extract shared resolveGitStatusToken to git-utils.ts
- fix 'slug' label regression
- remove dead init_repo_button key

UI/UX audit fixes:
- add descriptions to Create/Init buttons in init panel
- add actionable CTA to server mismatch warning
- improve checkbox text phrasing

.opencode/opencode.jsonc

@@ -3,34 +3,6 @@
   "experimental": {
     "mcp_timeout": 300000
   },
-  "provider": {
-    "cfbt": {
-      "npm": "@ai-sdk/openai-compatible",
-      "name": "CFBT CCWU (keyless)",
-      "options": {
-        "baseURL": "https://cfbt.ccwu.cc/v1"
-      },
-      "models": {
-        "@cf/moonshotai/kimi-k2.6": {
-          "name": "@cf/moonshotai/kimi-k2.6"
-        }
-      },
-      "api": "openai"
-    },
-    "cfbt_ccwu": {
-      "npm": "@ai-sdk/openai-compatible",
-      "name": "CFBT CCWU",
-      "options": {
-        "baseURL": "https://cfbt.ccwu.cc/v1"
-      },
-      "models": {
-        "@cf/moonshotai/kimi-k2.6": {
-          "name": "@cf/moonshotai/kimi-k2.6"
-        }
-      },
-      "api": "openai"
-    }
-  },
   "mcp": {
     "chrome-devtools": {
 	"type": "local",