feat: add support for build args in spec.yaml files

[danbarr]

Summary

Implements dockyard-side support for build args as described in #189. This allows spec.yaml files to specify additional CLI arguments that are baked into the container entrypoint.

Changes

• Added args field to MCPServerPackageSpec struct
• Updated generateDockerfile() to pass args to BuildFromProtocolSchemeWithName
• Updated documentation in README.md and docs/packaging.md with examples

Implementation Details

The args field is optional and accepts an array of strings:

spec:
  package: "@example/mcp-server"
  version: "1.0.0"
  args:
    - "start"
    - "--flag"

These arguments are passed to the toolhive BuildFromProtocolSchemeWithName function, which appends them to the container entrypoint. For example, with the above spec, the generated Dockerfile will have:

ENTRYPOINT ["npx", "@example/mcp-server", "start", "--flag"]

Benefits

• Required CLI arguments are baked into the container, preventing users from accidentally overwriting them
• Solves the issue where thv run -- args overwrites default args instead of appending
• Works seamlessly with the updated toolhive BuildFromProtocolSchemeWithName that now supports the buildArgs parameter

Testing

Tested with local builds to verify args are correctly passed through to the generated Dockerfile.

Closes #189

[github-actions]

🔒 MCP Security Scan Results

✅ adb-mysql-mcp-server

• Status: Passed
• Tools scanned: 3
• Result: No security issues detected

✅ agentql-mcp

• Status: Passed
• Tools scanned: 0
• Result: No security issues detected

✅ arxiv-mcp-server

• Status: Passed
• Tools scanned: 4
• Result: No security issues detected

✅ astra-db-mcp

• Status: Passed
• Tools scanned: 16
• Result: No security issues detected

✅ aws-diagram

• Status: Passed
• Tools scanned: 3
• Result: No security issues detected

✅ aws-documentation

• Status: Passed
• Tools scanned: 3
• Result: No security issues detected

✅ blender-mcp

• Status: Passed
• Tools scanned: 21
• Result: No security issues detected

✅ brightdata-mcp

• Status: Passed
• Tools scanned: 0
• Result: No security issues detected

✅ browserbase-mcp-server

• Status: Passed
• Tools scanned: 9
• Result: No security issues detected

✅ chroma-mcp

• Status: Passed
• Tools scanned: 13
• Result: No security issues detected

✅ chrome-devtools-mcp

• Status: Passed
• Tools scanned: 26
• Result: No security issues detected

✅ context7

• Status: Passed
• Tools scanned: 2
• Result: No security issues detected

✅ graphlit-mcp-server

• Status: Passed
• Tools scanned: 0
• Result: No security issues detected

✅ heroku-mcp-server

• Status: Passed
• Tools scanned: 0
• Result: No security issues detected

✅ ida-pro-mcp

• Status: Passed
• Tools scanned: 48
• Result: No security issues detected

✅ launchdarkly-mcp-server

• Status: Passed
• Tools scanned: 0
• Result: No security issues detected

✅ magic-mcp

• Status: Passed
• Tools scanned: 0
• Result: No security issues detected

✅ mcp-clickhouse

• Status: Passed
• Tools scanned: 0
• Result: No security issues detected

✅ mcp-jetbrains

• Status: Passed
• Tools scanned: 0
• Result: No security issues detected

✅ mcp-neo4j-aura-manager

• Status: Passed
• Tools scanned: 0
• Result: No security issues detected

✅ mcp-neo4j-cypher

• Status: Passed
• Tools scanned: 3
• Result: No security issues detected

✅ mcp-neo4j-memory

• Status: Passed
• Tools scanned: 0
• Result: No security issues detected

✅ mcp-server-box

• Status: Passed
• Tools scanned: 0
• Result: No security issues detected

✅ mcp-server-circleci

• Status: Passed
• Tools scanned: 16
• Result: No security issues detected

✅ mcp-server-neon

• Status: Passed
• Tools scanned: 0
• Result: No security issues detected

✅ netbird

• Status: Passed
• Tools scanned: 0
• Result: No security issues detected

✅ notion

• Status: Passed
• Tools scanned: 19
• Result: No security issues detected

✅ onchain-mcp

• Status: Passed
• Tools scanned: 10
• Result: No security issues detected

✅ phoenix-mcp

• Status: Passed
• Tools scanned: 19
• Result: No security issues detected

✅ playwright-mcp

• Status: Passed
• Tools scanned: 22
• Result: No security issues detected

✅ sentry-mcp-server

• Status: Passed
• Tools scanned: 0
• Result: No security issues detected

✅ supabase-mcp-server

• Status: Passed
• Tools scanned: 0
• Result: No security issues detected

✅ tavily-mcp

• Status: Passed
• Tools scanned: 0
• Result: No security issues detected

---

Summary: Scanned 33 MCP server(s), all passed security checks. ✅

[danbarr]

Note I didn't include the "start" build-time arg for launchdarkly as part of this PR, we'll need to coordinate that change along with a corresponding registry update to remove it from the default runtime args so we don't duplicate the arg.