build: add local just workflow

Add a justfile for the common fcry developer commands. The run recipe is
variadic and uses just positional arguments so program flags are forwarded
through cargo run without needing a second separator.

Keep the default release profile debuggable and checked, then move the
stripped, LTO-enabled artifact settings into the production profile. This
keeps day-to-day release builds easier to inspect while preserving an explicit
production build recipe for optimized distributable binaries.

The clippy recipe uses workspace, all-target, all-feature coverage and denies
warnings so the task runner matches the stricter local verification path.

Test Plan:
- cargo clippy
- cargo clippy --benches
- cargo clippy --tests
- cargo +nightly fmt
- just --fmt --check
- just run --help
- just clippy
- git diff --cached --check

Refs: none

justfile

@@ -0,0 +1,33 @@
+set positional-arguments
+
+run *args:
+    cargo run -- "$@"
+
+build:
+    cargo build
+
+build-release:
+    cargo build --release
+
+build-production:
+    cargo build --profile production
+
+fmt:
+    cargo +nightly fmt
+    tombi format
+    just --fmt
+
+_fix:
+    cargo fix
+    cargo clippy --fix
+
+fix: _fix fmt
+
+clippy:
+    cargo clippy --workspace --all-targets --all-features -- -D warnings
+
+test:
+    cargo test --workspace
+
+clean:
+    cargo clean