Promptware defense added against Brainworm-class prompt-injection attacks

What this changes for operators

• Operators running the agent against untrusted content (web, repos, MCP tool output) gain a built-in defense layer they should validate against their own injection test cases rather than assume blanket coverage.
• 19 security-tagged issues were closed in the same release, so the upgrade is the gate for these protections; staying on prior versions leaves the injection surface unmitigated.
• Verification path: upgrade to v0.15.0 and run known Brainworm-class injection patterns to confirm the defense triggers before exposing the agent to untrusted input.