feat(scoring): transition workflow learning and fix history UX (#39)

- add transition scoring engine to learn sequential workflows per
directory using command skeletons
- prioritize current active git branch over older branches in
suggestions
- restore strict chronological order for history navigation and bypass
AI re-ranking
- add in-memory session history for instant access to just-run commands
- fix PTY prompt not syncing when using arrow keys in the history menu
- fix history tie-breaker to properly prioritize newer commands by
assigning larger IDs
- fix potential mutex deadlock between bufferMu and pty write during
history navigation
- fix workspace git detection to remove depth limits and correctly
identify repositories with detached HEADs
- fix SQLite connection leaks in frecency queries
- fix global state leaks in history tests by snapshotting and restoring
registry states
- modernize string prefix checks using strings.CutPrefix

internal/scoring/skeleton.go

@@ -0,0 +1,23 @@
+package scoring
+
+import (
+	"strings"
+
+	"github.com/versenilvis/iris/spec"
+)
+
+// ExtractSkeleton extracts the subcommand skeleton of a command string for transition tracking.
+// If a spec is registered, it walks the subcommand tree.
+// If no spec is registered (or fallback occurs), it returns the first token (binary name).
+// Never returns empty string unless input has no tokens.
+func ExtractSkeleton(buf string) string {
+	if skeleton, ok := spec.TryExtractSkeleton(buf); ok && skeleton != "" {
+		return skeleton
+	}
+
+	fields := strings.Fields(buf)
+	if len(fields) == 0 {
+		return ""
+	}
+	return fields[0]
+}