EANCH-WP-0001 T05: umbrella cutover complete + pure subpath exports

Add ./selectors and ./types subpath exports so node-env consumers get a
pdfjs-free entry (the umbrella roundtrip test uses them). Update README status
to 'extracted; umbrella consumes this package'. Mark T05 done; record the
blocker as resolved. Umbrella verified green (typecheck, 95 tests, build) at
citation-evidence@d145148.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

package.json

@@ -1,5 +1,5 @@
 {
-  "name": "evidence-anchor",
+  "name": "@citation-evidence/evidence-anchor",
   "version": "0.1.0",
   "private": true,
   "description": "Selector creation, resolution, re-anchoring, and highlight/scroll contracts for the citation-evidence ecosystem.",
@@ -18,6 +18,8 @@
   ],
   "exports": {
     ".": "./src/index.ts",
+    "./selectors": "./src/selectors/index.ts",
+    "./types": "./src/types.ts",
     "./pdf": "./src/pdf/index.ts"
   },
   "scripts": {