chore(config): governance and config foundation (#292)

* chore(config): governance and config foundation (PR #272 split 1/6)

Add repository governance and configuration files:
- CODEOWNERS: review authority model
- ISSUE_TEMPLATE: Copilot task template
- PULL_REQUEST_TEMPLATE: comprehensive review checklist
- .env.example: environment variable documentation
- .tool-versions: asdf/mise compatibility (Node 20, Python 3.12)
- .gitignore: expanded coverage (build, test, Python, tmp)
- .markdownlint.json: add MD009 trailing whitespace rule
- VERSION: 0.1.0

This is PR 1 of 6 from the PR #272 decomposition plan.
Dependency chain: PR-1 → PR-2 → PR-3 → PR-4/5/6 (parallel)

* chore(config): remove fork-specific CODEOWNERS from upstream PR

CODEOWNERS references @alfraido86-jpg (fork owner). Submitting this to
upstream would override @affaan-m's review authority. CODEOWNERS belongs
in the fork only, not in upstream contributions.

Ref: SAM finding F9 (run-048 audit)

* chore: address CodeRabbit review feedback on PR #292

- Scope markdownlint config to repo files (globs pattern)
- Add pre-commit hook checkbox to PR template

Ref: CodeRabbit review on PR #292

* fix(config): address CodeRabbit nitpicks N2 and N3

N2: Move pre-commit hooks checkbox higher in security checklist.
N3: Replace global MD009 disable with scoped config (br_spaces: 2).

* fix(config): use recursive glob for node_modules exclusion (N4)

.env.example

@@ -0,0 +1,38 @@
+# .env.example — Canonical list of required environment variables
+# Copy this file to .env and fill in real values.
+# NEVER commit .env to version control.
+#
+# Usage:
+#   cp .env.example .env
+#   # Then edit .env with your actual values
+
+# ─── Anthropic ────────────────────────────────────────────────────────────────
+# Your Anthropic API key (https://console.anthropic.com)
+ANTHROPIC_API_KEY=
+
+# ─── GitHub ───────────────────────────────────────────────────────────────────
+# GitHub personal access token (for MCP GitHub server)
+GITHUB_TOKEN=
+
+# ─── Optional: Docker platform override ──────────────────────────────────────
+# DOCKER_PLATFORM=linux/arm64  # or linux/amd64 for Intel Macs / CI
+
+# ─── Optional: Package manager override ──────────────────────────────────────
+# CLAUDE_CODE_PACKAGE_MANAGER=npm  # npm | pnpm | yarn | bun
+
+# ─── Session & Security ─────────────────────────────────────────────────────
+# GitHub username (used by CI scripts for credential context)
+GITHUB_USER="your-github-username"
+
+# Primary development branch for CI diff-based checks
+DEFAULT_BASE_BRANCH="main"
+
+# Path to session-start.sh (used by test/test_session_start.sh)
+SESSION_SCRIPT="./session-start.sh"
+
+# Path to generated MCP configuration file
+CONFIG_FILE="./mcp-config.json"
+
+# ─── Optional: Verbose Logging ──────────────────────────────────────────────
+# Enable verbose logging for session and CI scripts
+ENABLE_VERBOSE_LOGGING="false"