🔧 Drop the redundant knip entry pattern

knip derives the public entry from package.json `exports` and resolves
it to src/index.ts itself, so naming the file in `entry` is redundant:
maintain:knip reported it as a configuration hint, and the scan is now
silent. Verified the barrel is still treated as the entry — the scope
is clean with and without dist/, and with src/index.test.ts removed.

Supersedes the workaround recorded in development/tooling.md, which
silenced an unused-file report for the barrel that the current entry
derivation no longer produces. Rewrite the section to state the
behaviour and keep the rejected `paths` mapping.

knip.json

@@ -1,5 +1,5 @@
 {
     "$schema": "./node_modules/knip/schema.json",
-    "entry": ["src/index.ts", "scripts/*.ts"],
+    "entry": ["scripts/*.ts"],
     "ignoreDependencies": ["@runwisp/pubv"]
 }