Possible gap in fallback scan: `time` and `watch` in DISPLAY_COMMANDS may allow dangerous commands to go undetected

[ryosandesu]

Description

While exploring how the fallback scan works, I noticed that time and watch are included in DISPLAY_COMMANDS in src/core/analyze/constants.ts. Commands in this list skip the fallback scan, which is intended for display-only commands like echo or cat that don't execute their arguments.

However, time and watch actually execute their arguments as commands, so dangerous commands wrapped by them currently go undetected.

I'm not sure if this is an intentional design decision, so I wanted to raise it as a discussion before assuming it's a bug.

Example

$ bunx cc-safety-net explain "git reset --hard"

INPUT
  git reset --hard

STEP 1 ─ Split shell commands
  Segment 1: ["git","reset","--hard"]                                                                                       
 
STEP 2 ─ Match rules                                                                                                        
  Rule:   rules-git.ts:analyzeGit()
  Result: MATCHED

RESULT
  Status: BLOCKED
  Reason: git reset --hard destroys all uncommitted changes permanently. Use
          'git stash' first.                                                                                                

$ bunx cc-safety-net explain "time git reset --hard"

INPUT
  time git reset --hard

STEP 1 ─ Split shell commands
  Segment 1: ["time","git","reset","--hard"]
                                                                                                                            
  ✓ Allowed (no matching rules)
                                                                                                                            
RESULT          
  Status: ALLOWED

$ bunx cc-safety-net explain "watch git reset --hard"

INPUT
  watch git reset --hard
                                                                                                                            
STEP 1 ─ Split shell commands
  Segment 1: ["watch","git","reset","--hard"]                                                                               
                
  ✓ Allowed (no matching rules)

RESULT
  Status: ALLOWED

Root Cause (if this is a bug)

In src/core/analyze/segment.ts, the fallback scan is skipped for commands in DISPLAY_COMMANDS:

if (!DISPLAY_COMMANDS.has(normalizedHead)) {
  // fallback scan
}

Since time and watch are in this list, their arguments are never analyzed.

Potential Fix

Removing time, watch (and timeout for Linux users) from DISPLAY_COMMANDS would allow the fallback scan to analyze their arguments.

Note on Scope

This fits the project's goal of preventing accidental data loss by coding agents. While the likelihood of a coding agent intentionally combining time or watch with a destructive command is low, it could happen unintentionally — for example, running time rm -rf ./build to measure cleanup duration.