ci: Add comprehensive CI quality gates

- New ci.yml workflow: rust-format, clippy, rust-test, security-audit, frontend-lint
- rustfmt.toml: strict formatting rules (edition 2021, max_width 100, grouped imports)
- clippy.toml: lint configuration with complexity thresholds
- eslint.config.js: ESLint 9 flat config for TypeScript/React
- build.yml: now only triggers on v* tags (ci.yml handles master/PR)
- package.json: updated lint script for ESLint 9 flat config

Quality gates run on every push to master and every PR:
1. Rust Format Check (cargo fmt --check --all)
2. Clippy Lints (pedantic + deny warnings)
3. Rust Unit Tests (cargo test --workspace --all-features)
4. Security Audit (cargo audit)
5. Frontend Lint (ESLint + TypeScript type check)

rustfmt.toml

@@ -0,0 +1,24 @@
+# Linux Patch Manager - Rust Formatting Configuration
+# Run: cargo fmt --check (CI) or cargo fmt (fix)
+
+edition = "2021"
+max_width = 100
+hard_tabs = false
+tab_spaces = 4
+newline_style = "Unix"
+use_small_heuristics = "Default"
+reorder_imports = true
+reorder_modules = true
+remove_nested_parens = true
+fn_single_line = false
+where_single_line = false
+imports_granularity = "Crate"
+group_imports = "StdExternalCrate"
+normalize_doc_attributes = true
+wrap_comments = true
+comment_width = 80
+indent_style = "Block"
+trailing_comma = "Vertical"
+match_block_trailing_comma = true
+blank_lines_lower_bound = 0
+blank_lines_upper_bound = 1