feat(ci): Add Forgejo CI/CD pipeline for linting and building

- Automated linting with rustfmt and clippy
- Automated building and testing
- Automated Docker image builds
- Clippy and rustfmt configuration files

backend/clippy.toml

@@ -0,0 +1,27 @@
+# Clippy configuration
+
+# Allow certain warnings for development
+ambiguous-glob-reexports = "allow"
+cast-lossless = "allow"
+doc-markdown = "warn"
+empty-structs-with-brackets = "warn"
+explicit-auto-deref = "warn"
+if-then-some-else-none = "warn"
+match-wildcard-for-single-variants = "warn"
+missing-errors-doc = "warn"
+missing-panics-doc = "warn"
+missing-safety-doc = "warn"
+semicolon-if-nothing-returned = "warn"
+unreadable-literal = "warn"
+unused-self = "warn"
+used-underscore-binding = "warn"
+
+# Deny certain lints
+missing-docs-in-private-items = "warn"
+unwrap-used = "warn"
+expect-used = "warn"
+indexing-slicing = "warn"
+panic = "deny"
+unimplemented = "warn"
+todo = "warn"
+unreachable = "warn"