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

root/suggestions.go

@@ -76,6 +76,13 @@ func MergeResults(query string, mode string) []spec.Suggestion {
 		}
 	}
 
+	if mode == "history" && normalizedQuery == "" {
+		if len(deduped) > maxSugg {
+			deduped = deduped[:maxSugg]
+		}
+		return deduped
+	}
+
 	if aiSugg := GetCurrentAISuggestion(); aiSugg != nil {
 		normalizedCmd := strings.TrimSpace(aiSugg.Cmd)
 		if normalizedCmd != "" && normalizedCmd != normalizedQuery && strings.HasPrefix(strings.ToLower(normalizedCmd), strings.ToLower(normalizedQuery)) {
@@ -105,7 +112,7 @@ func MergeResults(query string, mode string) []spec.Suggestion {
 	ctxTimeout, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
 	defer cancel()
 	store, _ := scoring.GetFrecencyStore()
-	signals := scoring.CollectSignals(ctxTimeout, cwd, query, rootCmd, store)
+	signals := scoring.CollectSignals(ctxTimeout, cwd, query, rootCmd, store, getPrevSkeleton())
 	scored := scoring.Score(deduped, signals)
 
 	finalResults := make([]spec.Suggestion, 0, len(scored))