feat: strengthen v0.3 security detection quality

[Adulph3]

Summary

• extend bounded supply-chain analysis to uvx and uv tool run, exact Python selectors, relevant --from/--with options, combined POSIX shell flags, and Windows command suffixes
• normalize documented Codex mixed env_vars entries and report http_headers_helper as an explicit safe coverage limitation
• advance the ruleset to 1.1.0 while versioning only AF-SUPPLY-001 and AF-SUPPLY-002
• add safe, vulnerable, and mixed examples, an educational security lab, detector documentation, and a security-gap register

Local validation

• npm ci, typecheck, lint/package/boundary checks, build, and catalog linkage: passed
• complete suite: 347/347 passed
• security suite: 43/43 passed
• coverage: 100% lines, 92.73% branches, 100% functions
• benchmark: p50 412.87 ms, p95 469.55 ms, RSS 160,595,968 bytes
• package dry-run/pack and allowlist inspection: passed
• isolated consumer imports, CLI, doctor, and clean scan: passed
• clean/safe/vulnerable/mixed scans: deterministic across repeated runs
• pre-import no-execution/no-runtime-network probe: zero instrumented calls; sentinel not executed; canary not leaked
• production dependency audit: zero vulnerabilities

Boundaries

This PR does not merge main, create a tag or GitHub Release, publish to npm, or change production runtime behavior outside the scoped detection-quality work. Remaining limitations are documented in docs/SECURITY_GAPS.md; SARIF and a first-party GitHub Action remain deferred.