fix: critical security hardening and RSR compliance cleanup

Security fixes:
- Remove hardcoded 'changeme' DB password fallback in setup.sh;
  now fails hard if WORDPRESS_DB_PASSWORD env var is not set
- Change SQL policy engine default from fail-open (Audit) to
  fail-closed (Block) for unknown tables
- Fix table matching from substring to exact match, preventing
  wp_comments_backdoor from matching wp_comments
- Add recursive subquery table extraction to prevent policy
  evasion via nested SELECTs
- Enable SSL verification in WordPress plugin for non-loopback
  agent connections (was unconditionally disabled)
- Rename derive_key_hkdf_shake512 to derive_key_hkdf_sha3_256
  to match actual algorithm (was misleading)
- Fix broken SQL policy fuzz target (called non-existent
  evaluate() method, now uses correct analyze() API)

RSR compliance:
- Rename AI.a2ml to 0-AI-MANIFEST.a2ml (standard naming)
- Create .well-known/ with security.txt, humans.txt, ai.txt
- Add .github/CODEOWNERS with crypto and eBPF review gates
- Delete redundant .machines_readable/6scm/ (canonical copy
  is in .machine_readable/ only)
- Remove duplicate MAINTAINERS.md (keeping .adoc)
- Remove duplicate root FUNDING.yml (keeping .github/FUNDING.yml)

Code quality:
- Add // SAFETY: comments to all 15 unsafe blocks in eBPF XDP
  firewall documenting bounds-check reasoning
- Add 6 new tests for fail-closed default, exact matching,
  DROP/ALTER blocking, DELETE/UPDATE policy enforcement

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: hyperpolymath

.github/CODEOWNERS

@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-FileCopyrightText: 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
+#
+# CODEOWNERS — defines review requirements for pull requests
+# https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/about-code-owners
+
+# Default owner for everything
+* @hyperpolymath
+
+# Crypto code requires explicit review
+crates/wharf-core/src/crypto.rs @hyperpolymath
+
+# eBPF kernel code requires explicit review
+crates/wharf-ebpf/ @hyperpolymath
+
+# Security-sensitive files
+SECURITY.md @hyperpolymath
+.well-known/ @hyperpolymath
+deploy/ @hyperpolymath

.machines_readable/6scm/AGENTIC.scm

@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-FileCopyrightText: 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
+#
+# AI system declaration for Project Wharf
+# See: 0-AI-MANIFEST.a2ml for full AI integration protocol
+
+User-agent: *
+Allow: /
+
+# AI agents should read the AI manifest first:
+# - 0-AI-MANIFEST.a2ml (root)
+# - .machine_readable/STATE.scm (current project state)
+# - .machine_readable/AGENTIC.scm (agent constraints)
+#
+# This project uses neurosymbolic CI/CD (Hypatia) and
+# gitbot-fleet for automated remediation.

.machines_readable/6scm/ECOSYSTEM.scm

@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-FileCopyrightText: 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
+#
+# humanstxt.org
+
+/* TEAM */
+Lead: Jonathan D.A. Jewell
+Site: https://github.com/hyperpolymath
+Location: United Kingdom
+
+/* SITE */
+Software: Project Wharf — The Sovereign Web Hypervisor
+Standards: PMPL-1.0-or-later, RSR (Rhodium Standard Repository)
+Components: wharf-cli, yacht-agent, wharf-ebpf
+Languages: Rust, Nickel, PHP, Bash

.machines_readable/6scm/META.scm

@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: PMPL-1.0-or-later
+# SPDX-FileCopyrightText: 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
+#
+# Security contact information per RFC 9116
+# https://www.rfc-editor.org/rfc/rfc9116
+
+Contact: mailto:security@hyperpolymath.net
+Expires: 2027-03-01T00:00:00.000Z
+Preferred-Languages: en
+Canonical: https://github.com/hyperpolymath/project-wharf/.well-known/security.txt
+Policy: https://github.com/hyperpolymath/project-wharf/blob/main/SECURITY.md