feat(ms-ai-architect): add plugin to open marketplace (v1.5.0 baseline)

Initial addition of ms-ai-architect plugin to the open-source marketplace.
Private content excluded: orchestrator/ (Linear tooling), docs/utredning/
(client investigation), generated test reports and PDF export script.
skill-gen tooling moved from orchestrator/ to scripts/skill-gen/.

Security scan: WARNING (risk 20/100) — no secrets, no injection found.
False positive fixed: added gitleaks:allow to Python variable reference
in output-validation-grounding-verification.md line 109.

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

plugins/ms-ai-architect/CHANGELOG.md

@@ -0,0 +1,29 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [0.4.0] - 2026-02-07
+
+### Note
+First formal version. This plugin was previously unversioned. It has significant functionality but no tests, no formal onboarding, and has only been used by one person.
+
+### What exists today
+- 145+ reference documents across 14 categories for RAG-based architecture guidance
+- 6 specialized agents: research, security assessment, cost estimation, ADR writer, license mapper, diagram generation
+- 13 commands: research, compare, cost, license, security, poc, adr, migrate, utredning, generate-skills, diagram, setup, help
+- Cosmo Skyberg architect persona
+- MCP integration with Microsoft Learn for fact verification
+- Covers: Copilot family, Power Platform AI, Azure AI Foundry, Azure AI Services, Semantic Kernel, Microsoft Agent Framework
+- Session logging with ADR reminders
+- Architecture Decision Record (ADR) generation in MADR v3.0 format
+
+### Known gaps (blocking 1.0)
+- No automated tests for any command or agent
+- No onboarding guide for new users
+- Windows: hooks are bash-only, no PowerShell equivalents
+- Cosmo Skyberg persona assumes KTG-specific context
+- Reference documents may be outdated (no refresh mechanism)
+- External verification: nobody else has installed or used this