feat(python): add asyncio port with shared conformance replay

[lan17]

Python applications can now use DialCache's explicit request scopes, layered caching, runtime policy, and tracked Redis invalidation through an asyncio-native package for Python 3.11+.

The API retains source-reviewed gcache conveniences (cached, id_arg, argument adapters, context managers, aget, and ainvalidate) while implementing DialCache's behavioral and wire contracts. The port includes coalescing, deadline and cancellation ownership, stale recovery, shadow validation, compression, and a borrowed-client Redis/Cluster adapter.

Also adds independent Python replay of all 17 shared profiles, completion fingerprint checks, native and real-server CI, packaging, and Python examples throughout the shared documentation. python/API-DESIGN.md records the gcache revision and API choices.

Python CI measures native and real Redis/Valkey/Cluster coverage with separate production-source LCOV reports. Both Python versions upload under the python Codecov flag using OIDC on PRs and main pushes; reports are retained as CI artifacts, and the README includes a Python coverage badge.

Local validation

Validated source commit: 4c1290393fded92e39608eb77e49992ea0427042.

• make check: all four language checks, package checks, documentation build, and audit gates passed.
• Complete shared corpus regeneration and committed Quint fixture checks passed.
• make formal-python: 7,759 conformance cases passed, including 6,022 generated/regression histories, 244 scenarios, 1,477 protocol vectors, and 16 witness checks.
• Python 3.14: 2,200 native/wire/scenario/smoke tests passed. Python 3.11: 2,098 passed with 102 expected eager-task-feature skips; asyncio.eager_task_factory was introduced in Python 3.12.
• Real Redis and Valkey integration: 343 tests passed per server, including six-node Redis Cluster and TypeScript interoperability; zero skips.
• Minimum zstandard 0.23.0: 1,515 protocol cases passed. Redis adapter/routing checks passed with redis-py 5.0.0 and 6.4.0.
• Python 3.11 with minimum coverage.py 7.11.0: full native suite and repository-relative LCOV path checks passed. Native plus real-server reports cover 1,495 / 1,573 production lines (95.04%) locally.
• Shared validation/diagnostic tests, coverage acceptance and import-isolation tests, workflow actionlint, Ruff, and the wheel build passed. Coverage is a test-only package dependency.

Scope

The package is experimental and unpublished. The complete replay gate establishes finite shared conformance evidence; a Python-specific semantic mutation campaign is not yet registered. Cached wrappers are always awaitable, and applications own their event loop and Redis client lifecycle.

— Levicus 🤖

[codecov-commenter]

Codecov Report

❌ Patch coverage is 92.05340% with 125 lines in your changes missing coverage. Please review.
✅ Project coverage is 93.73%. Comparing base (9ff9973) to head (4c12903).

Files with missing lines	Patch %	Lines
python/dialcache/cache.py	91.83%	38 Missing and 26 partials ⚠️
python/dialcache/config.py	85.24%	16 Missing and 11 partials ⚠️
python/dialcache/protocol.py	93.19%	6 Missing and 7 partials ⚠️
python/dialcache/clock.py	65.21%	8 Missing ⚠️
python/dialcache/context.py	94.18%	3 Missing and 2 partials ⚠️
python/dialcache/key.py	97.19%	2 Missing and 1 partial ⚠️
python/dialcache/local.py	93.87%	3 Missing ⚠️
python/dialcache/serializer.py	92.59%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #200      +/-   ##
==========================================
- Coverage   94.00%   93.73%   -0.28%     
==========================================
  Files          65       77      +12     
  Lines        9774    11347    +1573     
  Branches      404      657     +253     
==========================================
+ Hits         9188    10636    +1448     
- Misses        563      641      +78     
- Partials       23       70      +47     

Flag	Coverage Δ
go	91.15% <ø> (ø)
python	92.05% <92.05%> (?)
rust	94.29% <ø> (ø)
typescript	96.56% <ø> (ø)

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