fix(ci): add uv to mise.toml and bump mise-action to v4

CI was failing because uv was not installed — .mise.toml only had
python but not the uv package manager. Also bumps jdx/mise-action
from v2 to v4.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: gracefullight

.github/workflows/ci.yml

@@ -42,7 +42,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: jdx/mise-action@v2
+      - uses: jdx/mise-action@v4
       - name: Install dependencies
         run: npm ci
         working-directory: apps/web
@@ -68,7 +68,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: jdx/mise-action@v2
+      - uses: jdx/mise-action@v4
       - name: Install dependencies
         run: uv sync --frozen
         working-directory: apps/api
@@ -89,7 +89,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: jdx/mise-action@v2
+      - uses: jdx/mise-action@v4
       - name: Analyze
         run: flutter analyze
         working-directory: apps/mobile

.mise.toml

@@ -1,5 +1,6 @@
 [tools]
 node = "22"
 python = "3.12"
+uv = "latest"
 flutter = "3"
 terraform = "1"