libra: add v0.4.0 (admin add-account UI + account-write hardening)

New catalog entry alongside v0.3.0 (kept resolvable for existing installs).
v0.4.0 = aiolabs/libra @ v0.4.0 (merge of #46):
admin add-account UI, server-side Beancount-coherent name validation,
metadata escaping, unconstrained Open directives, duplicate-detection
fix (libra-#48), unconstrained per-user accounts (libra-#49), ledger-only
recovery (libra-#50), entry-id identity (libra-#42).

archive: .../libra/archive/v0.4.0.zip
sha256:  2abf6160e64030b73a57b16c617e33414ef7338772e580b2a3ebb54ac7f833c4

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

extensions.json

@@ -345,6 +345,16 @@
             "archive": "https://git.atitlan.io/aiolabs/libra/archive/v0.3.0.zip",
             "hash": "c04c0999576d4ce1fd33a4c5eced1f5d9f6e62065100766fde39e0fe2e96c230"
         },
+        {
+            "id": "libra",
+            "repo": "https://git.atitlan.io/aiolabs/libra",
+            "name": "Libra",
+            "version": "0.4.0",
+            "short_description": "Double-entry accounting for collectives",
+            "icon": "https://git.atitlan.io/aiolabs/libra/raw/branch/main/static/image/libra.png",
+            "archive": "https://git.atitlan.io/aiolabs/libra/archive/v0.4.0.zip",
+            "hash": "2abf6160e64030b73a57b16c617e33414ef7338772e580b2a3ebb54ac7f833c4"
+        },
         {
             "id": "lnurlp",
             "repo": "https://github.com/lnbits/lnurlp",