docs: RTD hygiene — delete dead readthedocs.yaml, prune conf.py, add docs CI

[Jammy2211]

Summary

Phase A of the docs-infrastructure census (PyAutoLabs/PyAutoFit#1341): deletes the dead readthedocs.yaml (drifted py3.11 duplicate — RTD only reads .readthedocs.yaml), removes the dead html_context block from docs/conf.py (sphinx_rtd_theme-era, never read by Furo), gitignores Sphinx build artifacts (docs/_build, docs/api/generated, docs/api/_autosummary — my local builds showed they were never ignored), and adds a docs CI check as a thin caller into PyAutoHeart's new reusable docs-build.yml (PyAutoHeart#48), gated on warning-count regression against docs/sphinx_warning_baseline.txt (105).

Merge order: PyAutoHeart#48 merges first — the docs check here errors with "workflow not found" until it lands.

API Changes

None — docs/CI configuration only.

Test Plan

• PyAutoGalaxy suite: 962 passed (full, worktree)
• Sphinx before/after: 105 → 105 warnings, identical warning set; rendered pages text-identical
• After PyAutoHeart#48 merges: docs check green on this PR (baseline measured locally; one-time CI recalibration allowed with justification)

Validation checklist (--auto run)

• Effective level: supervised (header: supervised, cap: docs ≤ medium → safe)
• Plan: on the issue (docs: RTD hygiene — reconnect PyAutoFit RTD, converge conf.py, add docs CI PyAutoFit#1341), written at start; disclosed riders: .gitignore artifacts, warning-baseline file
• Gate: tests 962 pass · smoke n/a (docs+CI only, no script surface) · review CLEAN · Heart YELLOW within in-session ack at ship (4 pre-existing reasons listed on #1341)
• Human: plan sound in hindsight?
• Human: diff matches plan (no scope creep)?
• Human: merge, amend, or reject — then log the outcome

Full API Changes (for automation & release notes)

None — files touched: readthedocs.yaml (deleted), docs/conf.py, .gitignore, .github/workflows/docs.yml (new), docs/sphinx_warning_baseline.txt (new).

🤖 Generated with Claude Code

https://claude.ai/code/session_01GziFkivBHz1d11eFYUszmy