feat(smith): implement connect/disconnect/update/status CLI with local bundled templates

[nullhack]

Summary

• Implement smith CLI with connect, disconnect, update, status subcommands using argparse
• Add BundledTemplateSource using importlib.resources (local package, no network required)
• Add UrlTemplateSource with tar.gz/zip support via requests
• Add LocalTemplateSource for local directory template sources
• Implement granular agentic file filter (.opencode/agents/, .opencode/skills/, .opencode/knowledge/, .opencode/tools/) — excludes node_modules and other non-agentic content
• Separate AGENTIC_FILE_PATTERNS (granular) from GITIGNORE_PATTERNS (broad: .opencode/)
• Add --overwrite flag to connect command for replacing user-tracked files
• Add --from flag for specifying template source (bundled:temple8, local path, or URL)
• Replace print() with sys.stdout.write/sys.stderr.write in CLI (no # noqa: T201 needed)
• Add docstrings to all public modules, classes, and methods
• Use @pytest.mark.deprecated for deprecated BDD tests (a1b2c3d4, e5f6g7h8)
• Remove @id: tags from test docstrings (IDs are already in function names)
• Add URL source BDD examples (a2b3c4d5, e4f5g6h7)
• Add scripts/update-bundle.sh for syncing smith/data/ from temple8
• Add ADR-007 (local bundled template resolution), supersede ADR-006
• 85 tests passing, ruff clean, pyright clean

Key decisions

• ADR-007: Bundled template source uses importlib.resources to read from smith/data/ package — no network, no cache
• Agentic filter is granular to exclude node_modules/package.json from bundles
• requests is the only external runtime dependency (for URL source downloads)
• Gitignore patterns remain broad (.opencode/) for ignoring entire directories