build: generate crates/tui/CHANGELOG.md as a 15-release slice instead of a full manual copy

The /change command embeds this file into every binary via include_str!;
it now carries only recent releases (regenerated by scripts/sync-changelog.sh,
wired into the release checklist). The explicit-version test derives its
fixture versions from the embedded slice instead of hardcoding old ones.

crates/tui/src/commands/change.rs

@@ -869,11 +869,18 @@ Older release.\n";
     fn change_with_explicit_version_includes_previous_hint() {
         let tmp = tempfile::TempDir::new().unwrap();
         let mut app = make_app(&tmp, Locale::En, false);
-        let result = change(&mut app, Some("0.8.32"));
+        // Derive versions from the bundled changelog: it only embeds a recent
+        // slice of releases, so hardcoded versions would age out of it.
+        let explicit = extract_previous_version_number(DEEPSEEK_TUI_CHANGELOG)
+            .expect("bundled changelog should have a previous release");
+        let expected_prev =
+            extract_previous_version_number_after_version(DEEPSEEK_TUI_CHANGELOG, &explicit)
+                .expect("bundled changelog should have at least three releases");
+        let result = change(&mut app, Some(&explicit));
         assert!(!result.is_error);
         let msg = result.message.as_deref().unwrap_or("");
         assert!(
-            msg.contains("Previous version:") && msg.contains("0.8.31"),
+            msg.contains("Previous version:") && msg.contains(&expected_prev),
             "explicit version should show previous-version hint: {msg}"
         );
     }

docs/RELEASE_CHECKLIST.md

@@ -31,6 +31,10 @@ not enumerate.
       if there is something material the user must work around.
 - [ ] The entry mentions all referenced issue/PR numbers as `#NNNN` so the
       auto-linker on GitHub picks them up.
+- [ ] Run `scripts/sync-changelog.sh` to regenerate `crates/tui/CHANGELOG.md`
+      (the recent-releases slice embedded in the binary for `/change`). Do
+      not edit that file by hand, and do not copy the full root changelog
+      into it — older entries live in `docs/CHANGELOG_ARCHIVE.md`.
 
 ## 2. Version pins are in sync
 

scripts/sync-changelog.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env sh
+# Regenerate crates/tui/CHANGELOG.md from the workspace root CHANGELOG.md.
+# The /change command embeds this file into the binary via include_str!, so
+# it deliberately keeps only the most recent release sections.
+#
+# Usage: scripts/sync-changelog.sh [sections-to-keep]   (default: 15)
+set -eu
+KEEP="${1:-15}"
+root="$(cd "$(dirname "$0")/.." && pwd)"
+awk -v keep="$KEEP" '
+  /^\[/ && /\]: http/ { exit }
+  /^## \[/ { count++ }
+  count > keep { exit }
+  { print }
+' "$root/CHANGELOG.md" > "$root/crates/tui/CHANGELOG.md"
+printf '%s\n' \
+  '---' \
+  '' \
+  'Older releases: [CHANGELOG.md](https://github.com/Hmbown/CodeWhale/blob/main/CHANGELOG.md) and [docs/CHANGELOG_ARCHIVE.md](https://github.com/Hmbown/CodeWhale/blob/main/docs/CHANGELOG_ARCHIVE.md).' \
+  >> "$root/crates/tui/CHANGELOG.md"
+echo "wrote crates/tui/CHANGELOG.md ($(wc -l < "$root/crates/tui/CHANGELOG.md") lines, $KEEP sections kept)"