feat: make API node retry parameters configurable via environment variables

[christian-byrne]

PR Created by the Glary-Bot Agent

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Summary

• Adds COMFY_API_MAX_RETRIES, COMFY_API_RETRY_DELAY, and COMFY_API_RETRY_BACKOFF environment variables to override default retry parameters for all API node HTTP requests
• Users in regions with unstable networks (e.g. behind the GFW in China) can increase the retry budget to tolerate longer network interruptions
• Defaults remain unchanged (3 retries, 1.0s delay, 2.0x backoff) when env vars are not set
• Adds 10 unit tests

Context

Users in China experience LocalNetworkError failures because the default retry budget of 3 retries (~7s total) is insufficient for networks with intermittent connectivity. This change lets affected users self-mitigate by increasing retries:

COMFY_API_MAX_RETRIES=10 COMFY_API_RETRY_DELAY=2.0 python main.py

Changes

comfy_api_nodes/util/client.py:

• Adds _env_int() / _env_float() helpers that read env vars with fallback defaults
• Adds frozen _RetryDefaults dataclass and RETRY_DEFAULTS singleton
• Wires RETRY_DEFAULTS into sync_op, sync_op_raw default parameters

comfy_api_nodes/util/download_helpers.py:

• Wires RETRY_DEFAULTS into download_url_to_bytesio defaults (with max(5, RETRY_DEFAULTS.max_retries) floor)

comfy_api_nodes/util/upload_helpers.py:

• Wires RETRY_DEFAULTS into upload_file defaults

tests/test_retry_defaults.py — 10 tests:

• _env_int / _env_float: default, override, invalid value handling
• _RetryDefaults: hardcoded defaults, env override mechanism, explicit construction, frozen immutability

Verification

Backend Python utility — no browser testing applicable. All 10 unit tests pass. No new LSP diagnostics.

API Node PR Checklist

Scope

• Is API Node Change

Pricing & Billing

• Need pricing update
• No pricing update

If Need pricing update:

• Metronome rate cards updated
• Auto‑billing tests updated and passing

QA

• QA done
• QA not required

Comms

• Informed Kosinkadink