feat: rewrite gh-commit in Go with local Ollama backend

Replaces the Python/Crush/DuckDB implementation with a CGO-free Go binary:
cobra CLI, modernc.org/sqlite storage, huh/lipgloss UI, and speed-tuned raw
/api/generate calls (think:false, keep_alive, capped num_predict) against a
local qwen3.5:2b. Ships as a gh extension via cli/gh-extension-precompile.

cmd/refresh.go

@@ -0,0 +1,76 @@
+package cmd
+
+import (
+	"path/filepath"
+
+	"github.com/spf13/cobra"
+
+	"github.com/prdlk/gh-commit/internal/gitx"
+	"github.com/prdlk/gh-commit/internal/ui"
+)
+
+var refreshCmd = &cobra.Command{
+	Use:   "refresh",
+	Short: "Regenerate scopes from the current repository structure",
+	Args:  cobra.NoArgs,
+	RunE: func(_ *cobra.Command, _ []string) error {
+		repoPath, err := requireGit()
+		if err != nil {
+			return err
+		}
+		repoName := filepath.Base(repoPath)
+
+		hasScopes, err := store.HasScopes(repoPath)
+		if err != nil {
+			return err
+		}
+		if !hasScopes {
+			ui.Errorf("Repository not configured — run 'gh commit init' first")
+			return errAborted
+		}
+		if err := ensureAI(); err != nil {
+			return err
+		}
+
+		existing, err := store.Scopes(repoPath)
+		if err != nil {
+			return err
+		}
+		ui.MagentaBoldf("Refreshing scopes for %s...", repoName)
+		ui.Println()
+		ui.Infof("Current scopes:")
+		displayScopes(existing)
+		ui.Println()
+
+		if !ui.Confirm("Refresh scopes based on current structure?") {
+			ui.Dimf("Cancelled")
+			return nil
+		}
+
+		scopes := generateScopes(existing)
+		if scopes == nil {
+			return errAborted
+		}
+
+		ui.Println()
+		ui.Successf("✓ Generated updated scopes")
+		ui.Println()
+		ui.Magentaf("Updated scopes:")
+		displayScopes(scopes)
+		ui.Println()
+
+		if ui.Confirm("Apply these changes?") {
+			if err := store.SaveScopes(repoPath, repoName, scopes, gitx.GitignoreHash(repoPath)); err != nil {
+				return err
+			}
+			ui.Successf("✓ Updated scopes")
+		} else {
+			ui.Dimf("Changes not applied")
+		}
+		return nil
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(refreshCmd)
+}