fix: use temp file + quoted heredoc for shell-safe comment body

Review content may contain double quotes, $VAR, backticks, etc. that
break double-quoted shell arguments or trigger run_shell_command security
rejection. Replace direct string interpolation with a two-step approach:

1. Write body to temp file via quoted heredoc (<<'BODYEOF') which
   prevents ALL shell expansion
2. Reference file with -F body=@/tmp/pr-comment.txt in gh api calls
   and --body-file in gh pr review calls

Also update Step 5 to clean up all temp files.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/core/src/skills/bundled/review/SKILL.md

@@ -173,24 +173,27 @@ gh pr view {pr_number} --json headRefOid --jq '.headRefOid'
 
 Then, for each confirmed finding, post an **inline comment** on the specific file and line using `gh api`:
 
-**Note:** Do NOT use `$()` command substitution — it is blocked by `run_shell_command` security policy. Pass the body directly as a multi-line string in the `-f body=` argument:
+**Shell safety:** Review content may contain double quotes, `$VAR`, backticks, or other shell-sensitive characters. Do NOT interpolate review text directly into shell arguments. Instead, use a **two-step process**: write the body to a temp file using a quoted heredoc (which prevents all shell expansion), then reference the file with `-F body=@file`.
 
 ```bash
-# Single-line finding:
-gh api repos/{owner}/{repo}/pulls/{pr_number}/comments \
-  -f body="**[{severity}]** {issue description}
+# Step A: Write comment body to temp file (quoted heredoc — no shell expansion):
+cat > /tmp/pr-comment.txt <<'BODYEOF'
+**[{severity}]** {issue description}
 
-{suggested fix}" \
+{suggested fix}
+BODYEOF
+
+# Step B: Post single-line comment referencing the file:
+gh api repos/{owner}/{repo}/pulls/{pr_number}/comments \
+  -F body=@/tmp/pr-comment.txt \
   -f commit_id="{commit_sha}" \
   -f path="{file_path}" \
   -F line={line_number} \
   -f side="RIGHT"
 
-# Multi-line finding (e.g., line range 42-50):
+# For multi-line findings (e.g., line range 42-50), add start_line and start_side:
 gh api repos/{owner}/{repo}/pulls/{pr_number}/comments \
-  -f body="**[{severity}]** {issue description}
-
-{suggested fix}" \
+  -F body=@/tmp/pr-comment.txt \
   -f commit_id="{commit_sha}" \
   -f path="{file_path}" \
   -F start_line={start_line} \
@@ -199,6 +202,8 @@ gh api repos/{owner}/{repo}/pulls/{pr_number}/comments \
   -f side="RIGHT"
 ```
 
+Repeat Steps A-B for each finding, overwriting the temp file each time. Clean up the temp file in Step 5.
+
 If posting an inline comment fails (e.g., line not part of the diff, auth error), include the finding in the overall review summary comment instead.
 
 **Important rules:**
@@ -208,17 +213,23 @@ If posting an inline comment fails (e.g., line not part of the diff, auth error)
 - Include the severity tag (Critical/Suggestion/Nice to have) at the start of each comment
 - Include the suggested fix in the comment body when available
 
-After posting all inline comments, submit an overall review using the action that matches the verdict from Step 3:
+After posting all inline comments, write the review summary to a temp file and submit it using the action that matches the verdict from Step 3:
 
 ```bash
+# Write summary to temp file:
+cat > /tmp/pr-review-summary.txt <<'SUMMARYEOF'
+{summary + verdict text}
+SUMMARYEOF
+
+# Submit review with the matching action:
 # If verdict is "Approve":
-gh pr review {pr_number} --approve --body "{summary}"
+gh pr review {pr_number} --approve --body-file /tmp/pr-review-summary.txt
 
 # If verdict is "Request changes":
-gh pr review {pr_number} --request-changes --body "{summary}"
+gh pr review {pr_number} --request-changes --body-file /tmp/pr-review-summary.txt
 
 # If verdict is "Comment":
-gh pr review {pr_number} --comment --body "{summary}"
+gh pr review {pr_number} --comment --body-file /tmp/pr-review-summary.txt
 ```
 
 If there are **no confirmed findings**:
@@ -229,7 +240,7 @@ gh pr review {pr_number} --approve --body "No issues found. LGTM! ✅"
 
 ## Step 5: Restore environment
 
-If you checked out a PR branch in Step 1, restore the original state now: check out the original branch, `git stash pop` if changes were stashed, and remove the temp file.
+If you checked out a PR branch in Step 1, restore the original state now: check out the original branch, `git stash pop` if changes were stashed, and remove all temp files (`/tmp/pr-review-context.md`, `/tmp/pr-comment.txt`, `/tmp/pr-review-summary.txt`).
 
 This step runs **after** Step 4 to ensure the PR branch is still checked out when posting inline comments (Step 4 needs the correct commit SHA from the PR branch).