Publish topic guides to the wiki and document tabbed windows

Publish the guides from this repository to the GitHub Wiki. Organize them into Usage, Configuration and Development, with 15 separate configuration topics and redirects for the former website guide URLs.

Add a tabbed-windows guide covering grouping, switching tabs and taking windows out. Document the scrolling indicator's defaults and limits, and link the guide from the README, shortcuts and IPC pages. Update from main, including the latest tabbed-layout changes.

Separate Activities setup, configuration and publishing documentation. Review the guide prose with the unslop skill, keeping existing examples and heading links. The wiki workflow uses GitHub's built-in token to publish documentation changes on main.

Validation:

- 20 documentation tests pass, including README links and Activities/tab-indicator field coverage.
- The publisher builds 46 wiki pages; the site build and Python syntax checks pass.
- All 115 code examples from main are preserved.
- The Python suite passes: 90 tests passed and 31 opt-in integration tests skipped, with the system GI module available.

docs/configuration/session-protocols.md

@@ -0,0 +1,22 @@
+# Optional session protocols
+
+These are launch-time environment switches, not KDL keys. Enable only for
+trusted clients: `FERESE_ENABLE_INPUT_METHOD=1`,
+`FERESE_ENABLE_SHORTCUT_INHIBIT=1`, `FERESE_ENABLE_SCREENCOPY=1`.
+The installed session launcher enables screencopy for screenshots unless
+`FERESE_ENABLE_SCREENCOPY=0` is explicitly set in its environment. Setting it
+to `0` disables every path that can read the screen, including the built-in
+screenshot command, not just the Wayland protocol. A session launched by hand
+rather than through `ferese-session` needs `FERESE_ENABLE_SCREENCOPY=1` in its
+environment for screenshots to work.
+Text input is available by default; Ctrl+Alt+Escape releases an active shortcut
+inhibitor. Use `feresectl --help` for runtime control commands.
+
+Shell rounding is controlled in Settings → Appearance → Shell corner radius.
+The shell and compositor use the same squircle profile for fills, borders, shadows
+and blur masks. Small controls cap the radius to fit their size; circles and pills
+keep circular outlines. The measured profile has small tangent and curvature
+discontinuities at its internal segment joins. Window rounding remains under
+Settings → Windows. Shell rounding comes from `theme.geometry.shell-radius`,
+which defaults to 14 px. Panel corners follow their selected style and height,
+with optional overrides in the [panel configuration](../panel-configuration.md#background-outline-and-corners).