Fix shell quoting bug in tech-sweep-exec inline comment posting#

Problem#

Inline PR comments posted by tech-sweep-exec broke when the comment body contained newlines, double-quotes, or backticks. The root cause was using -f body='<text>' in gh api calls, which is not safe for multi-line or special-character strings.

Task / Link#

Closes #1544

Changes#

• Created scripts/tools/post-inline-comment.sh: reusable helper that constructs JSON via jq -n --arg and posts via gh api --input - (mirrors post-review.sh pattern)
• Updated tech-sweep-exec/SKILL.md: replaced unsafe -f body='<text>' pattern with post-inline-comment.sh reference and direct jq + --input - alternative
• Updated failure behavior in SKILL.md: inline POST failures now log-and-continue instead of halting all remaining actions
• Created scripts/tools/test-inline-comment-quoting.sh: dry-run regression test validating JSON construction with newlines, double-quotes, and backticks; supports --live flag for real API verification

Notes#

• SKILL.md is a prompt-level instruction file — changes take effect on the next agent invocation (no deployment required)
• post-inline-comment.sh must exist on the runner filesystem before the SKILL.md references it; S1 (script creation) was deployed before S2 (skill update)

Testing#

• Ran test-inline-comment-quoting.sh in dry-run mode — all 4 checks passed (well-formed JSON, double-quotes preserved, backticks preserved, newlines preserved)
• Manual live verification can be performed with --live --repo AgentSDE/ai-agents-sde --pr <pr_number> --commit <sha> --path <file> --line <line>