Add Pyodide worker hosting

[timkpaine]

Description

Add a Pyodide Web Worker host that keeps Python rendering and state work off the main thread while the browser runtime mounts and incrementally patches the DOM.

The example routes a Python-authored SendPatch action through a transports 0.7 client proposal and authoritative session, then renders the accepted state and applies the resulting component-tree diff without replacing live elements. The existing build matrix now produces and tests a Python 3.14 Pyodide wheel, including a real Playwright round trip.

This also updates Python, JavaScript, and Rust transports dependencies to 0.7 and prevents generated Pyodide wheels from being copied recursively into browser assets.

Type of Change

• Bug fix
• New feature
• Documentation update
• Refactor / code cleanup
• CI / build configuration
• Other (describe below)

Checklist

• Linting passes (make lint)
• Tests pass (make test)
• New tests added for new functionality
• Documentation updated (if applicable)
• Changelog / version bump (if applicable)

[github-actions]

Test Results

276 tests  +7   274 ✅ +5   28s ⏱️ ±0s
 15 suites +2     2 💤 +2 
  2 files   ±0     0 ❌ ±0 

Results for commit 6189c91. ± Comparison against base commit b13069b.

[codecov]

Codecov Report

❌ Patch coverage is 75.55556% with 22 lines in your changes missing coverage. Please review.
✅ Project coverage is 96.02%. Comparing base (b13069b) to head (6189c91).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
spaday/tests/test_pyodide.py	24.13%	22 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #135      +/-   ##
==========================================
- Coverage   96.95%   96.02%   -0.94%     
==========================================
  Files          36       39       +3     
  Lines        1972     2062      +90     
  Branches      146      150       +4     
==========================================
+ Hits         1912     1980      +68     
- Misses         38       60      +22     
  Partials       22       22              

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