feat: adapt Dify plugin to Calls API v2

[JJasonSun]

Summary

Implements ONES 14092 and updates the plugin to 0.2.0.

- Calls /v1, per-invocation random keys, legacy result parsing
+ Calls /v2, required business-stable keys, result/error/transcript parsing
- Wait for execution status or a non-null Goal Run result/error
+ Wait while result_status=pending; retain accepted IDs on read failures
+ Emit named Dify workflow outputs alongside JSON

Calls send one phone and a closed scalar result schema. Omitted region/locale remain omitted on replay. Goal endpoints stay on v1, with phone, flat variables, and after pagination. The credential probe uses v2 without creating a call or following redirects. Dry-run and live-call confirmation controls remain required. Missing or invalid keys stop before any CALL-E request and explain how to bind Dify's Idempotency Key to a saved business event ID; the README includes an upgrade example.

Keys may be UUIDs generated and saved upstream, then supplied through a Dify variable binding. Dify's tool context provides no durable logical-call ID across separate Workflow runs, so the plugin does not generate keys in KV storage or infer duplicates from matching phone/task inputs.

Evidence

• Before: Reproducing v2 responses against main loses summary/transcript; a final unavailable Goal Run with null result/error never resolves.
  After: 101 tests pass on Python 3.12 with Dify SDK 0.9.0 and 0.10.2, including unavailable/empty results, malformed responses, wait timeouts, network ambiguity, accepted-ID recovery, named workflow outputs, and invalid-key guidance without HTTP requests across all four creation tools.
• Native Dify plugin stdio execution against the real CALL-E service: one Calls v2 call and one published Goal Run completed with available results and transcripts. Exact replays before/after completion retain resource and telephone IDs; changed inputs with the same keys return 409. Calls also recover after a plugin process restart and preserve metadata.
• The extracted 0.2.0 package passes native checks for all four tools' invalid-key guidance, exact replay of the two existing real calls, and named-variable output equality. Editable installation, compilation, and Dify Plugin CLI 0.6.11 packaging pass.
• Dify Cloud Sandbox: the final 0.2.0 package passes two cache-cleared, four-node creation/wait → exact replay → output runs (13.436s and 4.187s) against the workflow's completed real call. Both retain the original API and Billing IDs, available result, eight-turn transcript, and metadata. Named result (Object) and call_id (String) reach the output node. Cloud validation covers the valid-key flow; invalid-key guidance and Goal Run live testing use the native runtime.

Merge Danger

Door: two-way

Reverting the plugin code/package does not undo accepted calls. Keep each Call ID, business key, and original inputs when recovering or rolling back.

Blast Radius: workflows

Existing Call creation nodes must supply a durable idempotency_key, including when the caller reruns a workflow after an uncertain submission. Check old explicit US/en-US hints, replace legacy recipient/attempt output mappings, and rename Goal listing cursor to after. Historical v1 Call IDs still require their original interface. Old self-hosted Dify versions were not tested.

[JJasonSun]

Acceptance screenshots (2026-10-16)

These screenshots document installation and upgrade replays of 0.2.2 on Dify Cloud. We completed real-call acceptance on 0.2.1. Both cache-cleared workflow reruns reused the original requests and call resources, with no additional calls. This comment records existing acceptance evidence; we did not rerun tests for this update.

CALL-E 0.2.2 installed:

Calls replay: SUCCESS in 4.743 seconds. API/Billing IDs, metadata, and named workflow outputs match the original complete result.

Goal Run replay: SUCCESS in 13.632 seconds. Goal Run/run/call IDs and the result match the original record. The workflow name retains the 0.2.1 label from the original real-call acceptance; the installed plugin is 0.2.2, as shown above.