chore(toolchain): install the pinned Rust toolchain in CI

.github/workflows/build.yml

@@ -23,7 +23,8 @@ jobs:
         with:
           bun-version: latest
 
-      - run: rustup toolchain install --profile minimal 1.97.1
+      - name: Install pinned Rust toolchain
+        run: rustup toolchain install
 
       - uses: Swatinem/rust-cache@v2
         with:

.github/workflows/libcalibre-tests.yml

@@ -19,7 +19,7 @@ jobs:
       - uses: actions/checkout@v5
 
       - name: Install Rust
-        run: rustup toolchain install --profile minimal 1.97.1
+        run: rustup toolchain install
 
       - name: Install cargo-llvm-cov
         uses: taiki-e/install-action@cargo-llvm-cov
@@ -42,7 +42,7 @@ jobs:
       - uses: actions/checkout@v5
 
       - name: Install Rust
-        run: rustup toolchain install --profile minimal 1.97.1
+        run: rustup toolchain install
 
       - name: Install cargo-llvm-cov
         uses: taiki-e/install-action@cargo-llvm-cov
@@ -105,7 +105,7 @@ jobs:
       - uses: actions/checkout@v5
 
       - name: Install Rust
-        run: rustup toolchain install --profile minimal 1.97.1
+        run: rustup toolchain install
 
       - uses: Swatinem/rust-cache@v2
         with:

.github/workflows/quality.yml

@@ -17,7 +17,8 @@ jobs:
         with:
           bun-version: latest
 
-      - run: rustup toolchain install --profile minimal 1.97.1
+      - name: Install pinned Rust toolchain
+        run: rustup toolchain install
 
       - uses: Swatinem/rust-cache@v2
         with:
@@ -45,11 +46,11 @@ jobs:
         with:
           bun-version: latest
 
-      - run: rustup toolchain install --profile minimal 1.97.1
+      - name: Install pinned Rust toolchain
+        run: rustup toolchain install
 
       - uses: Swatinem/rust-cache@v2
         with:
-          # using the default — we can bust the cache by changing this
           prefix-key: "v1-rust"
           workspaces: "."
 

.github/workflows/release.yml

@@ -153,7 +153,8 @@ jobs:
         with:
           bun-version: latest
 
-      - run: rustup toolchain install --profile minimal 1.97.1
+      - name: Install pinned Rust toolchain
+        run: rustup toolchain install
 
       - uses: Swatinem/rust-cache@v2
         with:

README.md

@@ -42,7 +42,9 @@ Download the `.dmg` from [Releases](https://github.com/everydaythingssoftware/ci
 
 ## Developing
 
-As a prerequisite, you'll need to install [Bun](https://bun.sh) and [Rust](https://www.rust-lang.org/tools/install).
+As a prerequisite, you'll need to install [Bun](https://bun.sh) and
+[rustup](https://rustup.rs). Rust is pinned by `rust-toolchain.toml`; run
+`rustup toolchain install` once in this repository to install it.
 
 Then, you can install the packages.
 
@@ -57,6 +59,15 @@ bun run dev
 # or just bun dev
 ```
 
+### Updating Rust
+
+Rust upgrades are intentional repository changes. Update the channel in
+`rust-toolchain.toml` and the workspace `rust-version` in `Cargo.toml`
+together — CI installs the committed toolchain and derives its cache key from
+the same file. Then run `bun format:check`, `bun lint`, and
+`cargo test --workspace` before merging. Keep crate editions unchanged unless
+an edition migration is planned separately.
+
 ### Lint & Formatting
 
 To lint all source code, run `bun lint`. To autoformat, run `bun format`.
@@ -98,4 +109,4 @@ Citadel can check for app updates and install them on request. Automatic update
 
 This project would not be possible without the north star created by Kovid Goyal, [Calibre](https://github.com/kovidgoyal/calibre). Without his hard work building such an extensive and powerful tool, Citadel would not exist.
 
-Huge thanks to [Kemie Guaida](https://kemielikes.design/), who created an excellent [Calibre redesign Figma prototype](https://old.reddit.com/r/Calibre/comments/udzumn/testing_a_new_interface_for_calibre/), from which Citadel takes inspiration. Thank you, Kemie!
+Huge thanks to [Kemie Guaida](https://kemielikes.design/), who created an excellent [Calibre redesign Figma prototype](https://old.reddit.com/r/Calibre/comments/udzumn/testing_a_new_interface_for_calibre/), from which Citadel takes inspiration. Thank you, Kemie!