fix: address active PR review comments

- plan.md: clarify JSON parsing instructions (extract first { line)
- common.sh: validate max_depth is a positive integer
- common.ps1: add ValidateRange(1, MaxValue) on -MaxDepth
- setup-plan.ps1: add ValidateRange(0, MaxValue) on -ScanDepth

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: sakitA

scripts/bash/common.sh

@@ -290,6 +290,10 @@ check_dir() { [[ -d "$1" && -n $(ls -A "$1" 2>/dev/null) ]] && echo "  ✓ $2" |
 find_nested_git_repos() {
     local repo_root="${1:-$(get_repo_root)}"
     local max_depth="${2:-2}"
+    if ! [[ "$max_depth" =~ ^[0-9]+$ ]] || [ "$max_depth" -eq 0 ]; then
+        echo "find_nested_git_repos: max_depth must be a positive integer" >&2
+        return 1
+    fi
 
     # Collect explicit paths from 3rd argument onward
     local -a explicit_paths=()

scripts/powershell/common.ps1

@@ -237,6 +237,7 @@ function Test-DirHasFiles {
 function Find-NestedGitRepos {
     param(
         [string]$RepoRoot = (Get-RepoRoot),
+        [ValidateRange(1, [int]::MaxValue)]
         [int]$MaxDepth = 2,
         [string[]]$ExplicitPaths = @()
     )

scripts/powershell/setup-plan.ps1

@@ -4,6 +4,7 @@
 [CmdletBinding()]
 param(
     [switch]$Json,
+    [ValidateRange(0, [int]::MaxValue)]
     [int]$ScanDepth = 0,
     [switch]$Help
 )

templates/commands/plan.md

@@ -60,7 +60,7 @@ You **MUST** consider the user input before proceeding (if not empty).
 
 ## Outline
 
-1. **Setup**: Run `{SCRIPT}` from repo root and parse JSON for FEATURE_SPEC, IMPL_PLAN, SPECS_DIR, BRANCH, and NESTED_REPOS. For single quotes in args like "I'm Groot", use escape syntax: e.g 'I'\''m Groot' (or double-quote if possible: "I'm Groot").
+1. **Setup**: Run `{SCRIPT}` from repo root and capture its stdout. The script may print informational lines (e.g., "Copied plan template…") before the JSON payload, so extract the first line starting with `{` and parse that JSON object to obtain FEATURE_SPEC, IMPL_PLAN, SPECS_DIR, BRANCH, and NESTED_REPOS. For single quotes in args like "I'm Groot", use escape syntax: e.g 'I'\''m Groot' (or double-quote if possible: "I'm Groot").
 
 2. **Load context**: Read FEATURE_SPEC and `/memory/constitution.md`. Load IMPL_PLAN template (already copied).