chore: update Dockerfile pinned versions

[github-actions]

Dependency Version Updates

This PR updates pinned versions in the Dockerfile and synchronizes release documentation:

• OPENCODE_VERSION: 1.17.15 → 1.17.18 (source: opencode-ai)
• PLAYWRIGHT_MCP_VERSION: 0.0.77 → 0.0.78 (source: @playwright/mcp)
• LEANCTX_VERSION: 3.9.2 → 3.9.4 (source: yvgude/lean-ctx)
• LEANCTX_SHA256: 12b6b99bec2f326920c7372b0bbe457cbac76fbe46d45abdf89dbbc247c17c96 → a02ec8dbbe6cde3ab7eb04fe987121240ad27c660412f543b54f26d084f3cd9f (source: yvgude/lean-ctx)

Documentation Updates

• README badges synchronized with pinned package versions
• CHANGELOG entry prepared for the next patch release

Test Results

Integration tests passed on the updated image.

Security Scan Results

No new critical Grype findings were introduced relative to the latest published release image.

Latest Package Changes

[{"name":"OH_MY_OPENAGENT_VERSION","current":"4.16.2","source":"npm","status":"changed","previous":"4.16.0"},{"name":"CODEGRAPH_VERSION","current":"1.3.1","source":"npm","status":"changed","previous":"1.3.0"}]

APT Updates

All packages are up to date

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Generated automatically by the Dependency Update workflow

[tryweb]

Auto-approve: routine dependency update PR.

• Changes limited to Dockerfile pinned versions, README badge, CHANGELOG, and test snapshot.
• All updates are patch/minor bumps (no major versions).
• LEANCTX_VERSION 3.9.2 → 3.9.4 with matching SHA256 update.
• No breaking changes; no business logic modifications.
• Workflow integration tests: 93 passed, 0 failed.
• Security scan: no new critical Grype findings.

Recommended for auto-merge.