♻️ Move script-header rationale into development/

branch.sh, finish.sh, release.sh, runner-image.sh and release-notes.sh
carried multi-paragraph 'how we got here / rejected' essays in comments. They
now live in the matching development/ category file, and each script keeps a
one-line pointer so the rationale is single-homed and cannot drift.

scripts/precompress.ts

@@ -9,6 +9,9 @@ import zlib from "node:zlib";
  * matching `Accept-Encoding` and falls back to the original for the rest.
  *
  * Usage: node --strip-types scripts/precompress.ts <dir> [<dir>...]
+ *
+ * Why sidecars rather than per-request compression: development/ci.md § Coverage
+ * serving.
  */
 
 /**