docs: cut the 1.1.0 changelog section

[shanforge]

Prepares the release notes for 1.1.0. This has to merge before the tag: the workflow
extracts the version's section from CHANGELOG.md for both Sparkle's release-notes pane
and the GitHub Release body, and with no ## [1.1.0] section it falls back to
## [Unreleased] — shipping whatever happens to be sitting there.

What changed

[Unreleased] → [1.1.0] - 2026-08-23.

Added what was missing. The Ask Logue work was the largest thing in this release and
had no entry at all — the Command Center island now runs the same agent as the main window
(tools and their results, approval prompts, dropped files, web search, Deep Research, a
kept conversation, and Open in Logue). Also missing: the sidebar hover actions (#54), the
pane sizing (#52), the Privacy tab's egress list, and the island fixes that came out of
click-testing rc.1.

Led with the extension, since it is the headline and the one thing that needs the
reader to go and do something — the Chrome Web Store link is in the notes, with a nudge to
leave a review.

Merged the two ### Changed headings the section had grown, and added a ### Fixed
section for the island work.

Credited every pull request with its author — 17 of them, @shanforge and @westerosweb.

One thing worth knowing

The credits are a list, not a table, on purpose. scripts/extract_release_notes.py has
no table support: rendered as a table, all seventeen rows collapsed into a single
unreadable <p> in the HTML Sparkle displays. I checked by rendering both formats — it now
produces 32 <li> items across four <ul>s, with the author links intact and no stray
pipe characters.

Verification

• python3 scripts/test_extract_release_notes.py — 24 tests pass (this is what CI runs).
• extract_release_notes.py --version 1.1.0 renders correctly in both markdown and
  html.
• No code changed, so nothing to build.

WhatsNewCatalog already carries its 1.1.0 block from #68, so nothing is needed there.