fix: make failed-post retry work — enum status mismatch

[Ooscaar]

Summary

Fixes zernio-dev/zernio-claude-plugin#1: the MCP retry path never recognized a failed post, so there was no working way to retry one — users had to delete and recreate.

Two bugs conspired:

1. posts_retry guard never matched. The post's status deserializes into a codegen'd plain Enum with an unstable positional name (Status10 in the released build, renumbered on every spec regen), while the guard compared against the handwritten PostStatus str-enum. Two different enum classes never compare equal in Python, so every failed post was rejected with is not in failed status (current: Status10.FAILED).
2. posts_retry_all_failed / posts_list_failed queried with a mangled filter. PostStatus.FAILED was passed through to httpx, which serializes params via str() — sending status=PostStatus.FAILED instead of status=failed. The API matched nothing, so the tools reported "No failed posts to retry".

Changes

Single commit on top of develop (branch was rebuilt and squashed; the OAuth discovery work previously on this branch is already in develop as d88b72c):

• codegen: add --use-subclass-enum to generate_models.py — generated enums are now (str, Enum), so members compare equal to their plain value and to the PostStatus twin (models regenerated; mixin-only diff, no renames).
• resources: unwrap Enum members to .value in _build_params / _build_payload — in the generator template (each generated resource carries its own shadowing copy) and in the handwritten BaseResource. Fixes every enum filter SDK-wide, e.g. the documented client.posts.list(status=PostStatus.FAILED).
• mcp: posts_retry compares plain status values and reports the clean value (current: scheduled) in the warning — robust even if codegen flags change.
• tests: unit tests pin enum unwrapping + value-compatibility; test_mcp_retry_regression.py drives the real MCP tools against a strict in-memory fake API (httpx.MockTransport, no network) that only matches the literal status=failed.

Testing

• Full suite: 184 passed, 14 skipped ✅
• The regression tests, run against the unfixed code, fail with the exact error messages from the issue (is not in failed status (current: Status7.FAILED) / No failed posts to retry.) and pass with the fix; one test asserts status=failed is literally on the wire. ✅
• No public API changes: all 45 curated model re-exports verified by the generation script; wire values are byte-for-byte what the API always expected.

Consumer impact

No breaking changes. Enum-filtered list calls that silently returned wrong results now return correct ones, post.status == "failed" now behaves intuitively, and .value access is unchanged.

Follow-up (out of scope)

Root-cause cleanup in the API repo: name the post status as components/schemas/PostStatus in the OpenAPI spec so codegen stops emitting unstable StatusN names and the handwritten twin enum can be retired.

🤖 Generated with Claude Code