review fixes for v0.63.0

Caught during self-review of the nine polish items:

1. Recovery notice handled negative age ("-1 min ago") from clock skew or
   very fresh snapshots. Added "just now" branch for age < 1 minute.

2. Shortcuts overlay Diff Preview entries were invented:
   - Enter was documented as "Apply" but diff actually uses y / Y
   - "r: Reject" never existed (diff uses n / N / Esc)
   - "Tab: Toggle context lines" is wrong — Tab only toggles focus in the
     multi-file variant, and is unbound in single-file diff
   - "e: Edit before applying" was aspirational — no key handler exists
   Replaced with the real bindings: y, n/Esc, A, R, Tab (multi-only).

3. Error guidance regexes used bare HTTP status codes (401, 500, etc.)
   which would match "500ms latency" or any substring. Added \b word
   boundaries; 5xx now also requires a nearby keyword (error/server/
   gateway/unavailable/timeout) so random numbers don't trigger.

4. Tool progress bar truncation sliced by bytes, not runes. For Cyrillic
   or emoji output this could produce invalid UTF-8 before appending "…".
   Now converts to []rune before slicing.

Author: ginkida

internal/app/app.go

@@ -434,6 +434,9 @@ func (a *App) Run() error {
 			age := time.Since(snap.Timestamp).Round(time.Minute)
 			var ageStr string
 			switch {
+			case age < time.Minute:
+				// Clock skew or very fresh snapshot — avoid "-1 min ago"
+				ageStr = "just now"
 			case age < time.Hour:
 				ageStr = fmt.Sprintf("%d min ago", int(age.Minutes()))
 			case age < 24*time.Hour:

internal/ui/error_guidance.go

@@ -274,23 +274,24 @@ var errorGuidancePatterns = []ErrorGuidance{
 		Suggestions: []string{"The conversation is too long for this model", "Run /clear to start fresh, or /compact to summarize older messages", "Switch to a model with a larger context window via /model"},
 		Command:     "/compact",
 	},
-	// Authentication / API key
+	// Authentication / API key — use word boundaries on status codes so we
+	// don't match "401ms latency" etc.
 	{
-		Pattern:     regexp.MustCompile(`(?i)(invalid api key|authentication failed|unauthorized|401|403.*forbidden|api key.*invalid|authentication_error)`),
+		Pattern:     regexp.MustCompile(`(?i)(invalid api key|authentication failed|unauthorized|\b401\b|\b403\b.*forbidden|api key.*invalid|authentication_error)`),
 		Title:       "Authentication Failed",
 		Suggestions: []string{"Your API key is missing, invalid, or expired", "Run /auth to re-authenticate, or check your config file", "Verify the key at the provider's dashboard"},
 		Command:     "/auth",
 	},
 	// Quota / billing
 	{
-		Pattern:     regexp.MustCompile(`(?i)(quota.*exceed|insufficient.*credit|billing|payment.*required|402)`),
+		Pattern:     regexp.MustCompile(`(?i)(quota.*exceed|insufficient.*credit|billing|payment.*required|\b402\b)`),
 		Title:       "Quota or Billing Issue",
 		Suggestions: []string{"Your account has hit a usage cap or billing issue", "Check your provider dashboard for billing status", "Try a different provider via /model"},
 		Command:     "",
 	},
-	// Server errors (5xx)
+	// Server errors (5xx) — word boundaries so "500ms" doesn't trigger
 	{
-		Pattern:     regexp.MustCompile(`(?i)(500|502|503|504|internal server error|bad gateway|service unavailable|gateway timeout|overloaded|temporarily unavailable)`),
+		Pattern:     regexp.MustCompile(`(?i)(\b5\d\d\b.*(error|server|gateway|unavailable|timeout)|internal server error|bad gateway|service unavailable|gateway timeout|overloaded|temporarily unavailable)`),
 		Title:       "Provider Server Error",
 		Suggestions: []string{"The provider is experiencing issues — this is not your fault", "The retry logic already tried automatically", "Switch providers with /model, or try again in a few minutes"},
 		Command:     "",

internal/ui/shortcuts.go

@@ -65,9 +65,11 @@ func DefaultShortcuts() []ShortcutCategory {
 		{
 			Name: "Diff Preview",
 			Shortcuts: []Shortcut{
-				{Keys: []string{"Enter"}, Description: "Apply diff"},
-				{Keys: []string{"r"}, Description: "Reject diff"},
-				{Keys: []string{"Tab"}, Description: "Toggle context lines"},
+				{Keys: []string{"y"}, Description: "Apply this diff"},
+				{Keys: []string{"n", "Esc"}, Description: "Reject this diff"},
+				{Keys: []string{"A"}, Description: "Apply all remaining diffs"},
+				{Keys: []string{"R"}, Description: "Reject all remaining diffs"},
+				{Keys: []string{"Tab"}, Description: "Switch focus (multi-file only)"},
 			},
 		},
 		{

internal/ui/tool_progress_bar.go

@@ -156,9 +156,12 @@ func (m *ToolProgressBarModel) View(width int) string {
 	// non-empty line so the user sees live progress instead of stale head.
 	if m.currentStep != "" {
 		step := lastNonEmptyLine(m.currentStep)
-		maxLen := 60
-		if len(step) > maxLen {
-			step = step[:maxLen-1] + "…"
+		// Rune-aware truncation so multibyte chars (emoji, Cyrillic) don't
+		// get sliced mid-byte and render as replacement chars.
+		const maxRunes = 60
+		runes := []rune(step)
+		if len(runes) > maxRunes {
+			step = string(runes[:maxRunes-1]) + "…"
 		}
 		builder.WriteString(" ")
 		builder.WriteString(dimStyle.Render(step))