ci: improve workflows with stricter checks, caching, and idempotency

CI improvements:
- Add concurrency group to cancel redundant runs on same branch
- Add cargo cache to fmt job (was missing entirely)
- Add timeout-minutes: 5 to fast jobs (fmt, clippy, test) for fail-fast
- Change RUST_BACKTRACE from 'short' to '1' for better CI debuggability
- Pin push trigger to branches: [main] to avoid double-firing on PR merges
- Test minimum supported Neovim (0.11.0) instead of latest patch (0.11.3)

Release improvements:
- Enforce RUSTFLAGS: -D warnings at env level and in matrix rustflags
- Remove redundant checkout in release job (only needs env vars)
- Add release notes generation from git log since previous tag
- Make release creation idempotent (check if release exists before creating)
- Fix release_id not being set when release already exists

.gitea/workflows/ci.yaml

@@ -2,27 +2,43 @@ name: CI
 
 on:
   push:
+    branches: [main]
   pull_request:
 
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
 env:
   CARGO_TERM_COLOR: always
-  RUST_BACKTRACE: short
+  RUST_BACKTRACE: "1"
   RUSTFLAGS: -D warnings
 
 jobs:
   fmt:
     name: cargo fmt --check
     runs-on: ubuntu-latest
+    timeout-minutes: 5
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@1.83
         with:
           components: rustfmt
+      - uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            target
+          key: ${{ runner.os }}-cargo-fmt-${{ hashFiles('**/Cargo.lock', '**/Cargo.toml') }}
+          restore-keys:
+            - ${{ runner.os }}-cargo-fmt-
       - run: cargo fmt --all -- --check
 
   clippy:
     name: cargo clippy
     runs-on: ubuntu-latest
+    timeout-minutes: 5
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@1.83
@@ -35,13 +51,14 @@ jobs:
             ~/.cargo/git
             target
           key: ${{ runner.os }}-cargo-clippy-${{ hashFiles('**/Cargo.lock', '**/Cargo.toml') }}
-          restore-keys: |
-            ${{ runner.os }}-cargo-clippy-
+          restore-keys:
+            - ${{ runner.os }}-cargo-clippy-
       - run: cargo clippy --workspace --all-targets -- -D warnings
 
   test:
     name: cargo test
     runs-on: ubuntu-latest
+    timeout-minutes: 5
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@1.83
@@ -52,8 +69,8 @@ jobs:
             ~/.cargo/git
             target
           key: ${{ runner.os }}-cargo-test-${{ hashFiles('**/Cargo.lock', '**/Cargo.toml') }}
-          restore-keys: |
-            ${{ runner.os }}-cargo-test-
+          restore-keys:
+            - ${{ runner.os }}-cargo-test-
       - run: cargo test --workspace --all-targets
 
   keymaps:
@@ -74,15 +91,15 @@ jobs:
             ~/.cargo/git
             target
           key: ${{ runner.os }}-cargo-test-${{ hashFiles('**/Cargo.lock', '**/Cargo.toml') }}
-          restore-keys: |
-            ${{ runner.os }}-cargo-test-
-      - name: install Neovim 0.11 + Vim
+          restore-keys:
+            - ${{ runner.os }}-cargo-test-
+      - name: install Neovim + Vim
         run: |
           set -euo pipefail
-          # Apt's neovim is too old (Ubuntu LTS ships 0.6/0.7), missing
-          # `vim.lsp.get_clients` and rejecting `@group.modifier`
-          # highlight names. Pull the official static tarball instead.
-          NVIM_VER=v0.11.3
+          # Test the minimum supported Neovim version (0.11.0) so we
+          # catch API regressions at the bottom of the supported range.
+          # Pinning to a specific patch version; bump when 0.12 ships.
+          NVIM_VER=v0.11.0
           curl -fsSL -o /tmp/nvim.tar.gz \
             "https://github.com/neovim/neovim/releases/download/${NVIM_VER}/nvim-linux-x86_64.tar.gz"
           sudo tar -xzf /tmp/nvim.tar.gz -C /opt