fix: avoid lookbehind in application regexes for older WebKit

Application regex lookbehind prevented older WebKit from loading the startup module graph. Replace lookbehind with boundary checks across run/terminal links, SQL aliases, debugger targets and refactoring; preserve Unicode boundaries, UTF-16 offsets and empty-match progress. Add compatibility and regression tests.

Fixes #224
Refs #208

src/features/database/sql/complete.ts

@@ -68,7 +68,7 @@ export function quoteIdent(name: string, driver: DbDriver): string {
 
 /** A short alias for `table` not in `taken`: `order_items` → `oi`, `users` → `u`. */
 export function aliasFor(table: string, taken: ReadonlySet<string>): string {
-  const words = table.split(/[_\s.$-]+|(?<=[a-z])(?=[A-Z])/).filter(Boolean);
+  const words = table.replace(/([a-z])([A-Z])/g, "$1 $2").split(/[_\s.$-]+/).filter(Boolean);
   let base =
     words
       .map((w) => w[0]!)