refactor: unify path handling with SearchPath struct

[alexec]

Summary

Refactors path handling to use a unified SearchPath struct instead of separate functions for local and remote paths.

Changes

• Introduced SearchPath struct with BasePath, RulesSubPaths, TaskSubPaths, and DownloadedDir fields
• Replaced AllTaskSearchPaths, AllRulePaths, DownloadedRulePaths, and DownloadedTaskSearchPaths functions with:
  • DefaultSearchPaths(baseDir, homeDir) - returns search paths for default local paths
  • PathSearchPaths(dir) - returns search paths for a given directory (used for both local and remote)
  • NewSearchPathWithDefaults(basePath) - creates a SearchPath with default subpaths
• Replaced WithRemotePaths option with:
  • WithSearchPaths([]SearchPath) - sets search paths directly
• Unified local and remote path handling - both go through go-getter and are copied to temp directories
• Downloaded paths now use default subpaths via NewSearchPathWithDefaults instead of empty subpaths
• Added DownloadedDir field to SearchPath to track downloaded directories directly on the struct
• Removed downloadedDirs []string field from Context struct (replaced by DownloadedDir on SearchPath)
• Updated TaskSearchDirs() and RulesSearchDirs() to use DownloadedDir if set, otherwise BasePath
• Removed unnecessary check for empty subpaths (condition never occurs)
• Removed unused homeDir parameter from findTaskFile and findExecuteRuleFiles functions
• Removed isRemoteURL guard - all paths go through go-getter which handles both local and remote
• Updated all tests to use the new API
• Updated documentation

Benefits

• More flexible and extensible API
• Cleaner separation of concerns
• Unified handling of local and remote paths
• Explicit opt-in for default local paths via WithSearchPaths(DefaultSearchPaths(...))
• Consistent default subpaths for all paths
• Simplified function signatures by removing redundant parameters
• Better encapsulation - downloaded directory tracking is now part of SearchPath rather than separate state

[Copilot]

Pull request overview

This PR refactors the path handling system to use a unified SearchPath struct, replacing separate functions for managing local and remote paths. The refactoring introduces a cleaner, more flexible API where path searching is explicitly configured through options rather than being automatically included.

Key changes:

• Introduced SearchPath struct to unify path representation with BasePath, RulesSubPaths, and TaskSubPaths
• Replaced path helper functions with DefaultSearchPaths(baseDir, homeDir) and PathSearchPaths(dir)
• Changed CLI flag from -d to -P and replaced WithRemotePaths() with WithSearchPaths() and WithPath() options
• Unified local and remote path handling through go-getter for consistent behavior

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
pkg/codingcontext/paths.go	Introduces SearchPath struct and replaces individual path functions with unified DefaultSearchPaths() and PathSearchPaths() functions
pkg/codingcontext/context.go	Updates Context struct with searchPaths and paths fields; adds WithSearchPaths() and WithPath() options; updates findTaskFile() and findExecuteRuleFiles() to use new search path structure
pkg/codingcontext/remote.go	Renames downloadRemoteDirectory() to downloadPath() to reflect unified handling of both local and remote paths
pkg/codingcontext/context_test.go	Adds getTestSearchPaths() helper and updates all tests to use new API with explicit searchPaths configuration
pkg/codingcontext/README.md	Documents new SearchPath struct, DefaultSearchPaths(), PathSearchPaths(), WithSearchPaths(), and WithPath() functions
main.go	Changes CLI flag from -d to -P, retrieves homeDir for default search paths, and constructs options using new WithSearchPaths() and WithPath() API
integration_test.go	Updates integration test to use new -P flag instead of -d