feat(linux): scaffold cargo workspace with core, app, and postgres driver

Author: datlechin

.github/workflows/build-linux.yml

@@ -0,0 +1,46 @@
+name: Build Linux
+
+on:
+  push:
+    branches: [main, "linux/**", "docs/linux-**", "feat/linux-**"]
+    paths:
+      - "linux/**"
+      - ".github/workflows/build-linux.yml"
+  pull_request:
+    paths:
+      - "linux/**"
+      - ".github/workflows/build-linux.yml"
+
+jobs:
+  fast:
+    name: Fast checks
+    runs-on: ubuntu-24.04
+    defaults:
+      run:
+        working-directory: linux
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install system dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y \
+            build-essential \
+            pkg-config \
+            libgtk-4-dev \
+            libadwaita-1-dev \
+            libssl-dev \
+            libsecret-1-dev
+      - uses: dtolnay/rust-toolchain@1.92
+        with:
+          components: rustfmt, clippy
+      - uses: Swatinem/rust-cache@v2
+        with:
+          workspaces: linux
+      - name: Format check
+        run: cargo fmt --all -- --check
+      - name: Clippy
+        run: cargo clippy --all-targets -- -D warnings
+      - name: Build
+        run: cargo build --workspace
+      - name: Unit tests
+        run: cargo test --workspace --lib

linux/.gitignore

@@ -0,0 +1,3 @@
+target/
+*.swp
+.DS_Store

linux/CONTRIBUTING.md

@@ -22,7 +22,7 @@ cargo fmt --all                # format
 | `rustfmt` | `rustfmt.toml` at workspace root | Run before commit. Pre-commit hook enforces it. |
 | `clippy` | `clippy.toml` at workspace root | All workspace crates pass with `-D warnings`. New lints are negotiated per PR. |
 | Edition | 2024 | Set per workspace. Do not override per crate. |
-| MSRV | 1.83 | Pinned in `rust-toolchain.toml`. Bumped only with discussion. |
+| MSRV | 1.92 | Pinned in `rust-toolchain.toml`. Bumped only with discussion. |
 
 Conventions, beyond what `rustfmt` decides: