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/troubleshooting-map.md

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+# Troubleshooting map
+
+Fast mapping from symptom to likely cause and first action.
+
+## `dcr.toml file not found`
+
+Likely cause:
+- you are outside project root (or member root).
+
+First action:
+```sh
+pwd
+ls
+```
+Run DCR from directory that contains `dcr.toml`.
+
+## `Invalid config: missing [package]` / `missing [build]`
+
+Likely cause:
+- incomplete config in root project.
+
+First action:
+- ensure root `dcr.toml` includes `[package]`, `[build]`, and `[dependencies]`.
+- for workspace setups, keep these sections in root and add `[workspace]` additionally.
+
+## `Unknown build flag` or profile-flag errors
+
+Likely cause:
+- typo in flag or duplicate profile flag.
+
+First action:
+```sh
+dcr --help
+```
+Use only supported flags and at most one of `--debug` / `--release`.
+
+## Dependency include/lib path errors
+
+Likely cause:
+- path in `[dependencies]` does not exist.
+
+First action:
+- verify `path`, `include`, `lib` values.
+- if using profile placeholders, confirm expanded paths exist for selected profile.
+
+## `Cannot run library build`
+
+Likely cause:
+- `build.kind` is `staticlib` or `sharedlib`.
+
+First action:
+- switch `build.kind` to `bin`, or set `[run].cmd` if you intentionally need custom run command.
+
+## Build succeeds but output is stale
+
+Likely cause:
+- stale artifacts or generated files from previous runs.
+
+First action:
+```sh
+dcr clean --all
+dcr build --force
+```
+
+## `dcr --update` suggests package manager update
+
+Likely cause:
+- DCR binary is managed by pacman/AUR.
+
+First action:
+```sh
+yay -Syu dcr
+# or
+paru -Syu dcr
+```