chore(release): unwrap CHANGELOG paragraphs for GitHub Release notes (#180)

GitHub renders release-note Markdown with GFM hard breaks, so every
`\n` becomes `<br>`. The CHANGELOG is hard-wrapped at ~75 chars for
readable diffs, which renders as awkward visible line breaks on the
release page (see https://github.com/colbymchenry/codegraph/releases/tag/v0.7.10).

Add `scripts/extract-release-notes.mjs` to extract a version block
and join indented continuation lines into a single line per bullet.
Nested list items, headings, and link references are preserved.
`scripts/release.sh` now uses this helper instead of the inline awk
extractor — repo-level CHANGELOG.md viewing is unaffected because
CommonMark there treats newlines as spaces.

Also fix the 0.7.10 entry: "Two underlying fixes" -> "Three", "Rust
file-/level" broken hyphen, and move the closes/credit line above
the nested list so it doesn't strand as a top-level paragraph.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -42,24 +42,23 @@ and adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   …) accept `module::symbol` (Rust / C++ / Ruby), `Module.symbol`
   (TS / JS / Python), and `module/symbol` (path-style) — multi-level
   forms (`crate::configurator::stage_apply::run`) and Rust path
-  prefixes (`crate`, `super`, `self`) are handled. Two underlying
-  fixes:
+  prefixes (`crate`, `super`, `self`) are handled. Closes
+  [#173](https://github.com/colbymchenry/codegraph/issues/173). Thanks
+  to [@joselhurtado](https://github.com/joselhurtado) for the detailed
+  reproduction. Three underlying fixes:
     - The FTS5 query builder now treats `::` as a token separator
       instead of stripping it to nothing, so `stage_apply::run` no
       longer collapses to the unsearchable `stage_applyrun`.
     - `matchesSymbol` falls back to a file-path containment check when
-      `qualifiedName` doesn't carry the module hierarchy (Rust file-
-      level functions, Python free functions in a package): a `run`
-      in `src/configurator/stage_apply.rs` now matches
+      `qualifiedName` doesn't carry the module hierarchy (Rust
+      file-level functions, Python free functions in a package): a
+      `run` in `src/configurator/stage_apply.rs` now matches
       `stage_apply::run` because `stage_apply` appears as a path
       segment.
     - Qualified lookups that don't match the qualifier no longer fall
       through to fuzzy text matches — `stage_apply::nonexistent_fn`
       returns `null` instead of resolving to an unrelated `rollback`
       in the same file.
-  Closes [#173](https://github.com/colbymchenry/codegraph/issues/173).
-  Thanks to [@joselhurtado](https://github.com/joselhurtado) for the
-  detailed reproduction.
 
 [0.7.10]: https://github.com/colbymchenry/codegraph/releases/tag/v0.7.10