Delete upstream docs apparatus; rewrite README for the fork

The CDiT fork is single-household and was carrying an entire upstream
docs/ mkdocs site documenting features the fork has removed (sleep mode,
take-over-control, brightness_mode selector, YAML config). The README
mostly auto-generated from those pages via markdown-code-runner.

What's gone:

- docs/ — all 11 pages + assets + run_markdown_code_runner.py
- .github/workflows/docs.yml — zensical+shinylive GitHub Pages build
- .github/workflows/markdown-code-runner.yml — auto-edit of README from docs/
- .github/update-services.py / update-strings.py — would clobber the
  hand-edited services.yaml / strings.json
- scripts/update-generated-content — orchestrator for the above
- custom_components/adaptive_lighting/_docs_helpers.py + docs_gen.py —
  only used by the deleted markdown-code-runner
- zensical.toml — docs-site config
- "docs" dependency group in pyproject.toml (markdown-code-runner,
  shinylive, zensical, etc.) + lock regenerated

What's new:

- README.md rewritten to describe the fork's actual surface — 3 switches,
  4 number entities, 3 sensor entities per profile, 2 services (apply +
  change_switch_settings), entry-only setup, UI tuning, sun source.
  Preserves the existing "What's new in 2.1" / "2.2" block quotes.
- webapp/README.md annotated to flag the Shiny simulator models the
  upstream curve (with brightness_mode, sleep mode, etc.) and does not
  reflect the fork.
- CLAUDE.md command table no longer references update-generated-content.

Sensor.py + test_sensor_platform.py: incidental black reformat from the
lint pass (multi-arg function calls split per line).

Tests still pass (123/123). Lint clean. Sensors implementation
unchanged.

.github/workflows/docs.yml

@@ -1,64 +0,0 @@
-name: Documentation
-
-on:
-  push:
-    branches: [main]
-  pull_request:
-  workflow_dispatch:
-
-permissions:
-  contents: read
-  pages: write
-  id-token: write
-
-concurrency:
-  group: "pages"
-  cancel-in-progress: false
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v6
-
-      - name: Set up Python
-        uses: actions/setup-python@v6
-        with:
-          python-version: '3.14.2'
-
-      - name: Install uv
-        uses: astral-sh/setup-uv@v8.1.0
-
-      - name: Install dependencies
-        run: uv sync --group docs
-
-      - name: Build documentation
-        run: uv run zensical build
-
-      - name: Build webapp (simulator)
-        run: uv run shinylive export webapp webapp-site
-
-      - name: Integrate webapp into docs
-        run: |
-          # Copy webapp into docs site at /simulator/
-          mkdir -p site/simulator
-          cp -r webapp-site/* site/simulator/
-          echo "Webapp integrated at site/simulator/"
-
-      - name: Upload artifact
-        uses: actions/upload-pages-artifact@v5
-        with:
-          path: ./site
-
-  deploy:
-    if: github.ref == 'refs/heads/main' && github.event_name != 'pull_request'
-    environment:
-      name: github-pages
-      url: ${{ steps.deployment.outputs.page_url }}
-    runs-on: ubuntu-latest
-    needs: build
-    steps:
-      - name: Deploy to GitHub Pages
-        id: deployment
-        uses: actions/deploy-pages@v5

.github/workflows/markdown-code-runner.yml

@@ -1,48 +0,0 @@
-name: markdown-code-runner
-
-on:
-  push:
-    branches:
-      - main
-  pull_request:
-
-jobs:
-  markdown-code-runner:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Check out code from GitHub
-        uses: actions/checkout@v6
-        with:
-          repository: ${{ github.event.pull_request.head.repo.full_name || github.repository }}
-          ref: ${{ github.head_ref || github.ref }}
-          fetch-depth: 0
-
-      - name: Set up Python
-        uses: actions/setup-python@v6
-        with:
-          python-version: "3.14.2"
-
-      - name: Install uv
-        uses: astral-sh/setup-uv@v8.1.0
-
-      - name: Update generated content
-        run: ./scripts/update-generated-content
-
-      - name: Check for changes
-        run: |
-          if [ -n "$(git status --porcelain)" ]; then
-            if [ "${{ github.event_name }}" == "pull_request" ]; then
-              echo "::error::Auto-generated files are not up to date. Please run './scripts/update-generated-content' locally and push the changes."
-              exit 1
-            else
-              echo "Changes detected, committing and pushing..."
-              git add -u .
-              git config --local user.email "github-actions[bot]@users.noreply.github.com"
-              git config --local user.name "github-actions[bot]"
-              git commit -m "Update auto-generated content"
-              git pull --rebase
-              git push
-            fi
-          else
-            echo "No changes detected."
-          fi