feat: add native Qt support and dcr lint command; refactor architecture and integration tests

docs/commands/quality-commands.mdx

@@ -42,3 +42,18 @@ dcr fmt
 Processes: `src/**/*.{c,cpp,cxx,cc,h,hpp,hxx,hh}` and `tests/**/*.{c,cpp,cxx,cc,h,hpp,hxx,hh}`.
 
 Uses `.clang-format` at the project root (if present), otherwise default clang-format style.
+
+## `dcr lint`
+
+Runs `clang-tidy` on C/C++ source files for static analysis.
+
+```bash
+dcr lint              # show diagnostics
+dcr lint --fix        # apply fixes automatically
+dcr lint --help       # detailed help
+```
+
+Processes: `src/**/*.{c,cpp,cxx,cc}` and `tests/**/*.{c,cpp,cxx,cc}`.
+
+Without `--fix`, clang-tidy reports warnings and errors without modifying files.
+With `--fix`, clang-tidy applies automatic suggestions in place.

docs/reference/build-profiles.mdx

@@ -32,13 +32,22 @@ Set `inherit = false` to disable array inheritance (only profile's own arrays ar
 
 ## Built-in profiles
 
-| Profile | Default cflags |
+The default flags for each profile are composed from three config fields:
+
+| Field | debug default | release default |
+|-------|--------------|----------------|
+| `opt_level` | `"0"` | `"3"` |
+| `debug` | `true` | `false` |
+| `warnings` | `["all", "extra"]` | `[]` |
+
+Which produce the equivalent compiler flags:
+
+| Profile | Effective flags |
 |---------|---------------|
 | `debug` | `-O0 -g -Wall -Wextra -fno-omit-frame-pointer -DDCR_DEBUG` |
 | `release` | `-O3 -DNDEBUG` |
 
-These defaults are composed from the `opt_level`, `debug`, and `warnings` fields and can
-be overridden per-profile:
+Additional build options can be toggled per-profile:
 
 ```toml
 [build.release]

docs/reference/build-system.mdx

@@ -6,14 +6,37 @@ sidebar_label: Build system
 
 ## Compiler Backends
 
-DCR supports 4 compilation backends. Selection is automatic based on file extension.
+DCR supports 7 compilation backends. Selection is automatic based on file extension and `build.compiler` value.
 
 | Backend | Files | When used |
 |---------|-------|-----------|
 | `unix_cc` | `.c`, `.cpp`, `.cxx`, `.cc`, `.S` | gcc/clang on Linux/macOS/BSD |
 | `msvc` | `.c`, `.cpp`, `.cxx`, `.cc` | Windows (cl, clang-cl) |
 | `gas` | `.s` | ARM/ARM64 assembler (no preprocessor) |
-| `nasm` | `.asm` | x86/x86_64 assembler |
+| `nasm` | `.asm`, `.s` | x86/x86_64 NASM assembler |
+| `masm` | `.asm` | MASM (ml/ml64) on Windows |
+| `fasm` | `.asm`, `.fasm` | Flat Assembler |
+| `llvm_ir` | `.ll` | LLVM IR via `llc -filetype=obj` |
+
+## Qt Support
+
+DCR provides native Qt support for automatic meta-object handling (MOC, UIC, RCC).
+
+Enable it by setting `build.qt = true` in `dcr.toml`. DCR will automatically detect Qt-related files (`.ui`, `.qrc`, `.h` with `Q_OBJECT`) and process them.
+
+```toml
+[build]
+qt = true
+```
+
+*Note: Requires `qt6` modules (Core, Widgets, Gui, Svg) installed via `pkg-config`.*
+
+Advanced customization is still possible via `build.steps` if special handling is needed:
+
+```toml
+[build.steps]
+moc = "moc {in} -o {out}"
+```
 
 ### Unix CC
 
@@ -30,10 +53,13 @@ DCR supports 4 compilation backends. Selection is automatic based on file extens
 - Supports cl.exe and clang-cl.exe
 - Flags: `/std:`, `/Fo:`, `/Fe:`, `/I`, `/link`
 
-### GAS / NASM
+### GAS / NASM / MASM / FASM / LLVM-IR
 
 - GAS: `-I`, `-c -o`, `--defsym`
 - NASM: `-I`, `-o`, `-D`, `-f` (format: win64/elf64/macho64/macho32/elf32)
+- MASM: `/nologo /c /Fo<obj> <source>`
+- FASM: `<source> <output>` (output path is the object file)
+- LLVM IR: `-filetype=obj <source> -o <output>`
 
 ## Incremental Builds
 
@@ -48,7 +74,7 @@ Three levels of incrementality:
 - `thread::scope` for thread pool
 - Atomic task queue (`AtomicU64`)
 - Mutex on stdout (`OUTPUT_MUTEX`)
-- Thread count = `available_parallelism()`
+- Thread count = `available_parallelism()`, capped by `build.codegen-units` if set
 
 ## Build Kinds
 

docs/reference/dcr-toml.mdx

@@ -56,6 +56,10 @@ author = "John Doe"
 
 ## [build]
 
+...
+
+- `build.qt` — (bool) Enable automatic Qt meta-object handling (MOC, UIC, RCC). Requires `qt6` modules installed via `pkg-config`.
+
 | Field | Default | Description |
 |-------|---------|-------------|
 | `language` | `"c"` | `"c"`, `"c++"`, `"cpp"`, `"cxx"`, `"asm"` |
@@ -85,6 +89,7 @@ author = "John Doe"
 | `warnings` | `["all", "extra"]` (debug) / `[]` (release) | Warning flags (e.g. `"all"`, `"extra"`, `"pedantic"`) |
 | `panic` | `""` | Panic strategy: `"abort"` disables exceptions and unwind tables |
 | `codegen-units` | `""` | Max parallel compilation jobs (`"0"` = auto) |
+| `qt` | `false` | Enable automatic Qt meta-object handling (MOC, UIC, RCC) |
 
 Settings from raw config (not in typed struct):
 - `pkg_config` — list of pkg-config packages
@@ -101,6 +106,11 @@ cxx_standard = "c++23"
 compiler = "clang"
 kind = "sharedlib"
 cflags = ["-Wall", "-Wextra"]
+opt_level = "z"
+lto = true
+strip = true
+panic = "abort"
+codegen-units = "2"
 ```
 
 ## [toolchain]