feat: Update documentation with new sections for workspace guide, flags & environment, and troubleshooting map; enhance CLI reference and build/run notes for improved clarity.

docs/reference-and-help/workspace-guide.md

@@ -0,0 +1,53 @@
+# Workspace guide
+
+`[workspace]` lets you build related DCR projects in dependency order from one root.
+
+## Important rule
+
+Workspace root still needs a valid root project config:
+
+- `[package]`
+- `[build]`
+- `[dependencies]`
+
+`[workspace]` augments that root config; it does not replace required root sections.
+
+## Minimal example
+
+```toml
+[package]
+name = "root-app"
+version = "0.1.0"
+
+[build]
+language = "c"
+standard = "c11"
+compiler = "clang"
+kind = "bin"
+
+[dependencies]
+
+[workspace]
+core = { path = "./modules/core", deps = [] }
+net = { path = "./modules/net", deps = ["core"] }
+app = { path = "./modules/app", deps = ["core", "net"] }
+```
+
+Each member path must point to a directory containing its own `dcr.toml`.
+
+## Build behavior
+
+- Running `dcr build` in workspace root builds members in topological dependency order, then builds the root project.
+
+- Running `dcr clean --all` in workspace root cleans all members too.
+
+- `dcr gen` in workspace root includes root + members in generated outputs.
+
+## Common errors
+
+- `workspace.<name>.path does not contain dcr.toml`:
+  member path is wrong or config is missing.
+- `workspace dependency '<name>' not found`:
+  `deps` references unknown member.
+- `workspace dependency cycle at <name>`:
+  cyclic dependencies in member graph.