sites: raw fetch gets site handlers - standard URL form, per-website cleanup and CHECK hints as a code registry, learn.microsoft.com first, plus a sites settings section (#200); 10.0.0-beta.3

Files changed:
- tools/chemenu/sites/ (registry, learn-microsoft handlers), web_capture.py, commands/raw/fetch.py, config_shapes.py
- tests, fixture, raw/CONTRACT.md, tools/README.md, docs, CHANGES.md, VERSION

Files changed:
- CHANGES.md
- VERSION
- docs/how-to/ingest-a-source.md
- docs/reference/commands/README.md
- docs/reference/commands/raw-material-and-uploads.md
- docs/reference/configuration.md
- raw/CONTRACT.md
- tools/CONTRACT.md
- tools/README.md
- tools/chemenu/commands/raw/fetch.py
- tools/chemenu/config_shapes.py
- tools/chemenu/reference_doc.py
- tools/chemenu/sites/__init__.py
- tools/chemenu/sites/learn_microsoft.py
- tools/chemenu/tests/fixtures/learn_microsoft/oslicense-module.html
- tools/chemenu/tests/test_config_shapes.py
- tools/chemenu/tests/test_sites.py
- tools/chemenu/web_capture.py

Co-Authored-By: Claude Code <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SnAJ7Z3CpVD3PRbN73QtU2

docs/how-to/ingest-a-source.md

@@ -16,6 +16,12 @@ pick a directory:
 - **A web page** needs no download of your own. Name the URL to the agent, and
   `tools/wikitool raw fetch` puts two files into `incoming/`: the HTML exactly as received, and a
   text derived from it with a header recording where and when it was fetched.
+  For the pages of a website the stack knows - Microsoft Learn, for one - the tool fetches the
+  same page in the website's standard form (the English one, whatever language your link was in),
+  leaves the page's menus, sign-in notice and feedback footer out of the derived text, and prints
+  `CHECK` lines for what it could not do for you: the agent acts on those before it accepts the
+  capture. Your instance can switch such a handler off, choose another language and add hint lines
+  of its own per website; see [the configuration reference](../reference/configuration.md).
 - **A document that is not text** - a PDF, a Word, PowerPoint or Excel file, a mail (`.eml` or
   Outlook `.msg`) or a ZIP archive - is
   put into `incoming/` as it is. `tools/wikitool raw derive incoming/<file>` turns it into a folder with the