chore: remove stale dialyzer ignores and fix CI PLT caching

- Remove 5 unnecessary dialyzer ignore entries that no longer match warnings
- Narrow CI dialyzer cache from entire _build to PLT files only
- Add OTP/Elixir versions to cache key to prevent stale PLT on version bumps
- Add restore-keys fallback to GitHub Actions dialyzer cache

.dialyzer_ignore.exs

@@ -21,10 +21,6 @@
   # is called with a tuple that satisfies the runtime contract but violates the opaque type spec
   {"lib/aprsme_web/gettext.ex", :call_without_opaque},
 
-  # False positive: MapSet.t() is opaque; the @spec is correct at the semantic level but dialyzer
-  # sees through the opaque wrapper to the underlying map representation
-  {"lib/aprsme/packets/prepared_queries.ex", :contract_with_opaque},
-
   # False positive: to_float/1 has a %Decimal{} clause for completeness but dialyzer infers
   # nil | number() from the call sites in mobile_channel — the clause is defensive dead code
   {"lib/aprsme_web/channels/mobile_channel.ex"},
@@ -46,16 +42,5 @@
   # Mix.Project PLT limitations: Mix.Project.compile_path/0 and
   # Mix.Project.config/0 are not present in the dialyzer PLT, and Code.ensure_loaded
   # is treated as having an unmatched return when used for side-effect.
-  {"lib/mix_unused/analyzer.ex"},
-
-  # Phoenix LiveViewTest false positive: render_hook/3 and render/1 internally access
-  # view.ref which only exists on View, but the type specs say Element | View.
-  # Dialyzer can't narrow the live/3 return type from Element | View to just View.
-  {"test/aprsme_web/live/map_live/movement_test.ex"},
-
-  # Compiler type-checking false positives: these test files use patterns that trigger
-  # type warnings from the Elixir compiler. All are pre-existing and benign.
-  {"test/aprsme/packets_mic_e_test.exs"},
-  {"test/aprsme/packets_test.exs"},
-  {"test/aprsme/is_test.exs"}
+  {"lib/mix_unused/analyzer.ex"}
 ]

.forgejo/workflows/ci.yml

@@ -74,6 +74,8 @@ jobs:
     container: git.mcintire.me/graham/elixir-base:latest
     env:
       MIX_ENV: dev
+      OTP_VERSION: "29.0"
+      ELIXIR_VERSION: "1.20"
 
     steps:
       - name: Configure git for submodules
@@ -85,15 +87,15 @@ jobs:
         with:
           submodules: recursive
 
-      - name: Restore dependency and build caches
+      - name: Restore PLT cache
         uses: https://code.forgejo.org/actions/cache@v4
         with:
           path: |
             deps
-            _build
-          key: ${{ runner.os }}-dialyzer-${{ hashFiles('**/mix.lock') }}
+            _build/dev/*.plt
+          key: ${{ runner.os }}-dialyzer-otp${{ env.OTP_VERSION }}-elixir${{ env.ELIXIR_VERSION }}-${{ hashFiles('**/mix.lock') }}
           restore-keys: |
-            ${{ runner.os }}-dialyzer-
+            ${{ runner.os }}-dialyzer-otp${{ env.OTP_VERSION }}-elixir${{ env.ELIXIR_VERSION }}-
 
       - name: Fetch dependencies
         run: mix deps.get

.github/workflows/ci.yml

@@ -51,20 +51,24 @@ jobs:
     runs-on: ubuntu-latest
     env:
       MIX_ENV: dev
+      OTP_VERSION: "29.0"
+      ELIXIR_VERSION: "1.20"
     steps:
       - uses: actions/checkout@v4
         with:
           submodules: recursive
       - uses: erlef/setup-beam@v1
         with:
-          otp-version: "29.0"
-          elixir-version: "1.20"
+          otp-version: ${{ env.OTP_VERSION }}
+          elixir-version: ${{ env.ELIXIR_VERSION }}
       - uses: actions/cache@v4
         with:
           path: |
             deps
-            _build
-          key: ${{ runner.os }}-dialyzer-${{ hashFiles('mix.lock') }}
+            _build/dev/*.plt
+          key: ${{ runner.os }}-dialyzer-otp${{ env.OTP_VERSION }}-elixir${{ env.ELIXIR_VERSION }}-${{ hashFiles('mix.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-dialyzer-otp${{ env.OTP_VERSION }}-elixir${{ env.ELIXIR_VERSION }}-
       - run: mix local.hex --force
       - run: mix local.rebar --force
       - run: mix deps.get