feat(overlays): add file rename/delete + file glob pattern support (#391)

* Adds new non-spec overlays for manipulating loose files next to specs
* Adds file glob support to (most of) these non-spec overlays
* Adds a new afero.FS implementation that supports constraining updates to a target dir
* Adds various tests

Author: reubeno

docs/reference/overlays.md

@@ -28,11 +28,19 @@ These overlays modify non-spec source files directly. They cannot be used on `.s
 overlays are typically only used to modify loose files next to specs when standard patching mechanisms
 can't easily be used.
 
-| Type | Description | Required Fields |
-|------|-------------|-----------------|
-| `file-prepend-lines` | Prepends lines to a file | `file`, `lines` |
-| `file-search-replace` | Regex-based search and replace on a file | `file`, `regex` |
-| `file-add` | Copies a new file from a source location | `file`, `source` |
+For overlays that use the `file` field and may apply to multiple files, this field is
+interpreted as a glob pattern for files to match; the table below details this.
+Glob patterns support doublestar (`**`) for recursive matching (e.g., `**/*.conf` matches all `.conf` files in any subdirectory).
+For `file-search-replace`, the overlay is considered to have been correctly applied if it
+successfully makes a replacement to at least one matching file.
+
+| Type | Description | Required Fields | Interpretation of `file` field |
+|------|-------------|-----------------|--------------------------------|
+| `file-prepend-lines` | Prepends lines to a file | `file`, `lines` | Glob pattern for files to transform |
+| `file-search-replace` | Regex-based search and replace on a file | `file`, `regex` | Glob pattern for files to transform |
+| `file-add` | Copies a new file from a source location; **fails if destination already exists** | `file`, `source` | Name of destination file |
+| `file-remove` | Removes a file | `file` | Glob pattern for files to remove |
+| `file-rename` | Renames a file within the same directory | `file`, `replacement` | Name of file to rename |
 
 ## Field Reference
 
@@ -45,11 +53,13 @@ can't easily be used.
 | Section | `section` | The spec section to target (e.g., `%build`, `%install`, `%files`, `%description`) | `spec-prepend-lines`, `spec-append-lines`, `spec-search-replace` (optional) |
 | Package | `package` | The sub-package name for multi-package specs; omit to target the main package | All spec overlays (optional) |
 | Regex | `regex` | Regular expression pattern to match | `spec-search-replace`, `file-search-replace` |
-| Replacement | `replacement` | Literal replacement text; omit or leave empty to delete matched text | `spec-search-replace`, `file-search-replace` (optional) |
+| Replacement | `replacement` | Literal replacement text; capture group references like `$1` are **not** expanded. Omit or leave empty to delete matched text. | `spec-search-replace`, `file-search-replace`, `file-rename` |
 | Lines | `lines` | Array of text lines to insert | `spec-prepend-lines`, `spec-append-lines`, `file-prepend-lines` |
-| File | `file` | The name of the non-spec file to modify or add | `file-prepend-lines`, `file-search-replace`, `file-add` |
+| File | `file` | The name of the non-spec file to modify or add | `file-prepend-lines`, `file-search-replace`, `file-add`, `file-remove`, `file-rename` |
 | Source | `source` | Path to source file for `file-add`; relative paths are relative to the config file | `file-add` |
 
+> **Note:** For `file-rename`, the `replacement` field is a **filename only** (not a path). The file is renamed within its current directory.
+
 ## Examples
 
 ### Adding a Build Dependency
@@ -171,6 +181,23 @@ source = "files/mypackage/extra-config.conf"
 description = "Add custom configuration file"
 ```
 
+### Removing a File
+
+```toml
+[[components.mypackage.overlays]]
+type = "file-remove"
+file = "undesired.conf"
+```
+
+### Renaming a File
+
+```toml
+[[components.mypackage.overlays]]
+type = "file-rename"
+file = "oldname.conf"
+replacement = "newname.conf"
+```
+
 ## Validation
 
 Overlay configurations are validated when the config file is loaded. Validation checks:

internal/app/azldev/cmds/component/preparesources.go

@@ -17,7 +17,8 @@ import (
 type PrepareSourcesOptions struct {
 	ComponentFilter components.ComponentFilter
 
-	OutputDir string
+	OutputDir    string
+	SkipOverlays bool
 }
 
 func prepareOnAppInit(_ *azldev.App, sourceCmd *cobra.Command) {
@@ -48,6 +49,8 @@ func NewPrepareSourcesCmd() *cobra.Command {
 	_ = cmd.MarkFlagRequired("output-dir")
 	_ = cmd.MarkFlagDirname("output-dir")
 
+	cmd.Flags().BoolVar(&options.SkipOverlays, "skip-overlays", false, "skip applying overlays to prepared sources")
+
 	return cmd
 }
 
@@ -73,7 +76,7 @@ func PrepareComponentSources(env *azldev.Env, options *PrepareSourcesOptions) er
 
 	component := comps.Components()[0]
 
-	event := env.StartEvent("Preparing sources", "component", component.GetName())
+	event := env.StartEvent("Preparing sources", "component", component.GetName(), "outputDir", options.OutputDir)
 	defer event.End()
 
 	var sourceManager sourceproviders.SourceManager
@@ -89,7 +92,7 @@ func PrepareComponentSources(env *azldev.Env, options *PrepareSourcesOptions) er
 		return fmt.Errorf("failed to create source preparer:\n%w", err)
 	}
 
-	err = preparer.PrepareSources(env, component, options.OutputDir)
+	err = preparer.PrepareSources(env, component, options.OutputDir, !options.SkipOverlays)
 	if err != nil {
 		return fmt.Errorf("failed to prepare sources for component %q:\n%w", component.GetName(), err)
 	}

internal/app/azldev/core/componentbuilder/componentbuilder.go

@@ -123,7 +123,7 @@ func (b *Builder) prepSourcesForSRPM(
 		return "", fmt.Errorf("failed to create work dir for source preparation:\n%w", err)
 	}
 
-	err = b.sourcePreparer.PrepareSources(ctx, component, preparedSourcesDir)
+	err = b.sourcePreparer.PrepareSources(ctx, component, preparedSourcesDir, true /*applyOverlays?*/)
 	if err != nil {
 		return "", fmt.Errorf("failed to prepare sources:\n%w", err)
 	}