chore: add FVM config and update lockfile

- Add .fvmrc pinning Flutter 3.41.4
- Add .fvm/ to .gitignore
- Update pubspec.lock with latest transitive dependency versions

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/.fvmrc

@@ -0,0 +1,3 @@
+{
+  "flutter": "3.41.4"
+}

client/.gitignore

@@ -43,3 +43,6 @@ app.*.map.json
 /android/app/debug
 /android/app/profile
 /android/app/release
+
+# FVM Version Cache
+.fvm/

client/pubspec.lock

@@ -125,10 +125,10 @@ packages:
     dependency: transitive
     description:
       name: characters
-      sha256: f71061c654a3380576a52b451dd5532377954cf9dbd272a78fc8479606670803
+      sha256: faf38497bda5ead2a8c7615f4f7939df04333478bf32e4173fcb06d428b5716b
       url: "https://pub.dev"
     source: hosted
-    version: "1.4.0"
+    version: "1.4.1"
   checked_yaml:
     dependency: transitive
     description:
@@ -668,26 +668,26 @@ packages:
     dependency: transitive
     description:
       name: matcher
-      sha256: dc58c723c3c24bf8d3e2d3ad3f2f9d7bd9cf43ec6feaa64181775e60190153f2
+      sha256: dc0b7dc7651697ea4ff3e69ef44b0407ea32c487a39fff6a4004fa585e901861
       url: "https://pub.dev"
     source: hosted
-    version: "0.12.17"
+    version: "0.12.19"
   material_color_utilities:
     dependency: transitive
     description:
       name: material_color_utilities
-      sha256: f7142bb1154231d7ea5f96bc7bde4bda2a0945d2806bb11670e30b850d56bdec
+      sha256: "9c337007e82b1889149c82ed242ed1cb24a66044e30979c44912381e9be4c48b"
       url: "https://pub.dev"
     source: hosted
-    version: "0.11.1"
+    version: "0.13.0"
   meta:
     dependency: transitive
     description:
       name: meta
-      sha256: e3641ec5d63ebf0d9b41bd43201a66e3fc79a65db5f61fc181f04cd27aab950c
+      sha256: "23f08335362185a5ea2ad3a4e597f1375e78bce8a040df5c600c8d3552ef2394"
       url: "https://pub.dev"
     source: hosted
-    version: "1.16.0"
+    version: "1.17.0"
   mime:
     dependency: transitive
     description:
@@ -993,10 +993,10 @@ packages:
     dependency: transitive
     description:
       name: test_api
-      sha256: "522f00f556e73044315fa4585ec3270f1808a4b186c936e612cab0b565ff1e00"
+      sha256: "8161c84903fd860b26bfdefb7963b3f0b68fee7adea0f59ef805ecca346f0c7a"
       url: "https://pub.dev"
     source: hosted
-    version: "0.7.6"
+    version: "0.7.10"
   typed_data:
     dependency: transitive
     description: