fix(release): retain project API docs on Pages

[imathwy]

Summary

• retain every ReleaseSpec-owned API tree on GitHub Pages
• keep only verified external dependency API docs as stubs
• redirect omitted historical Verso links to the canonical version
• raise the operational Pages budget to 920 MB while enforcing a separate 1 GB hard limit

Validation

• SDK tests: 127 passed
• repository tests: 43 passed
• Ruff, py_compile, shell syntax, workflow YAML: passed
• real prior-release projection: 885,479,760 bytes; 5,111 project-owned files byte-identical; 0 project stubs; 1,454 external stubs; 105 valid history redirects

The new Release will import existing branch artifacts and rerun aggregate packaging only; no Lean/doc/Verso rebuild.