feat: show context bomb in chat transcript after compact with acknowledgment

cmd/run.go

@@ -68,13 +68,13 @@ func runHandler(cmd *cobra.Command, args []string) error {
 	dbPath, err := config.DBPath()
 	if err != nil {
 		logFn("[warn] cannot open cache: %v", err)
-		return runWithoutCache(cfg, proj, wm, logFn)
+		return runWithoutCache(cfg, proj, wm, postCompact, logFn)
 	}
 
 	store, err := cache.Open(dbPath)
 	if err != nil {
 		logFn("[warn] cache open error: %v", err)
-		return runWithoutCache(cfg, proj, wm, logFn)
+		return runWithoutCache(cfg, proj, wm, postCompact, logFn)
 	}
 	defer store.Close()
 
@@ -192,7 +192,7 @@ func runHandler(cmd *cobra.Command, args []string) error {
 }
 
 // runWithoutCache attempts an API fetch with no cache fallback.
-func runWithoutCache(cfg *config.Config, proj *project.Info, wm *project.WorkingMemory, logFn func(string, ...interface{})) error {
+func runWithoutCache(cfg *config.Config, proj *project.Info, wm *project.WorkingMemory, postCompact bool, logFn func(string, ...interface{})) error {
 	ctx, cancel := context.WithTimeout(context.Background(), 90*time.Second)
 	defer cancel()
 
@@ -218,7 +218,7 @@ func runWithoutCache(cfg *config.Config, proj *project.Info, wm *project.Working
 		return silentExit()
 	}
 
-	opts := tmpl.RenderOptions{MaxTokens: maxTokens, WorkingMemory: wm}
+	opts := tmpl.RenderOptions{MaxTokens: maxTokens, WorkingMemory: wm, PostCompact: postCompact}
 	output, _, err := tmpl.Render(graph, proj.Name, opts)
 	if err != nil {
 		logFn("[warn] render error: %v", err)

internal/hooks/hooks.go

@@ -187,7 +187,7 @@ func commandExistsInHooks(hookList []Hook, matches ...string) bool {
 // isAlreadyInstalled checks if ALL uncompact hooks are present.
 func isAlreadyInstalled(hooks map[string][]Hook) bool {
 	return commandExistsInHooks(hooks["Stop"], "uncompact run", "uncompact-hook.sh") &&
-		commandExistsInHooks(hooks["UserPromptSubmit"], "uncompact show-cache")
+		commandExistsInHooks(hooks["UserPromptSubmit"], "uncompact show-cache", "show-hook.sh")
 }
 
 // mergeHooks adds hooks from toAdd into existing, skipping any whose commands

internal/template/render.go

@@ -137,7 +137,27 @@ func Render(graph *api.ProjectGraph, projectName string, opts RenderOptions) (st
 	}
 
 	if opts.PostCompact {
-		note := fmt.Sprintf("\n\n> [uncompact] Context restored after compact (~%d tokens). Please acknowledge at the start of your response with exactly: \"✓ Uncompact: context restored (~%d tokens)\"", resultTokens, resultTokens)
+		buildNote := func(n int) string {
+			return fmt.Sprintf("\n\n> [uncompact] Context restored after compact (~%d tokens). Please acknowledge at the start of your response with exactly: \"✓ Uncompact: context restored (~%d tokens)\"", n, n)
+		}
+		note := buildNote(resultTokens)
+		noteTokens := countTokens(note)
+		if opts.MaxTokens > 0 && resultTokens+noteTokens > opts.MaxTokens {
+			budget := opts.MaxTokens - noteTokens
+			if budget < 1 {
+				budget = 1
+			}
+			if tokens <= budget {
+				result, resultTokens = fullText, tokens
+			} else {
+				truncated, truncatedTokens, truncErr := truncateToTokenBudget(graph, projectName, budget, graph.Stats.CircularDependencyCycles, opts.WorkingMemory)
+				if truncErr != nil {
+					return "", 0, truncErr
+				}
+				result, resultTokens = truncated, truncatedTokens
+			}
+			note = buildNote(resultTokens)
+		}
 		result += note
 		resultTokens = countTokens(result)
 	}

scripts/uncompact-hook.sh

@@ -38,10 +38,9 @@ OUTPUT="$("$UNCOMPACT" run --fallback --post-compact)"
 DISPLAY_CACHE="${TMPDIR:-/tmp}/uncompact-display-${UID:-$(id -u)}.txt"
 
 if [ -n "$OUTPUT" ]; then
-  CHAR_COUNT="${#OUTPUT}"
-  APPROX_TOKENS=$(( CHAR_COUNT / 4 ))
-
-  # Write to display cache — UserPromptSubmit hook will show this as a visible
-  # transcript message on the user's next message.
-  printf '%s\n\n[uncompact] Context restored (~%d tokens)\n' "$OUTPUT" "$APPROX_TOKENS" > "$DISPLAY_CACHE"
+  # Write securely and atomically to avoid disclosure/races.
+  umask 077
+  TMP_CACHE="$(mktemp "${DISPLAY_CACHE}.XXXXXX")" || exit 0
+  printf '%s\n' "$OUTPUT" > "$TMP_CACHE"
+  mv -f "$TMP_CACHE" "$DISPLAY_CACHE"
 fi