feat: add Suno Dify plugin

[acedatacloud-dev]

Adds the Suno Dify tool plugin in its own repository, using the earlier AceDataCloud/Dify service-specific conventions. Public plugin ID: acedatacloud/suno. Tools: suno_generate_audios, suno_task_retrieve.

The service icon, display name, bilingual tool parameters, acedata_bearer_token and explicit provider/tool/client files follow the existing integrations. Four icons are copied byte-for-byte from Dify before retirement PR #499; GPT Image uses the matching assets from GPTImageN8N. Asset paths and hashes are in tests/asset-and-convention-sources.json. Each client contains only its own service's payload mapping.

Generation submits asynchronous tasks; the task tool retrieves or waits without repeating a paid generation. Results include status/task_id/media_urls/result and the previous success/trace_id/data outputs. Completed images use native Dify image messages. Fixed HTTPS API, read-only token validation, no paid automatic retry or fallback, and sanitized errors/task results remain in place.

Validation:

• 15 tests passed, including SDK registration, credential mapping, pending/completed output messages, error masking and API payload validation; Ruff and git diff --check passed.
• Official CLI packaging and Marketplace Toolkit validation passed with no blocking failures. Package SHA256: 201cb2829bc31b7ddbe7cecd084020dc1981dd439a4ceea31ce37addd6974866.
• Real Dify CE 1.17.1 + daemon 0.6.10-local workflows previously completed generation/edit cases, usable-media decoding and exactly-once billing reconciliation. All nine paid input cases across the five plugins produce identical API payloads after this refactor.
• Real CE follow-up verified the new service identity/icon, bilingual metadata, authorization and completed-task output via console APIs. The same task IDs were reused, with no new paid generation. Images returned native Dify image files. Sanitized evidence: tests/e2e-alignment.json.

Official submission: langgenius/dify-plugins#3225 . Marketplace installation, browser UI and Dify Cloud are not yet verified. The README tool table defines the implemented scope; this PR does not restore every historical tool or the retired private deployment/publishing workflows. Source developed with AI assistance. No source PR merge or production deployment is performed by this update.