use better raw file handling and return resources

[SamMorrowDrums]

Closes #372

This PR attempts to address some initially poor choices for how do handle files and resources.

• Adds an API adaptor for raw file API
• uses text response for text files, and base64 response for binary
• Adds URL parsing so it works in all supported environments
• Uses resource responses (getting much better results in VSCode for example), we already have the resource handles for these and resources are the right pattern for this.
• Drops directory handling from the template resources (it just doesn't work well)
• Keeps the directory handling as a fallback for the tool version of get repo content.
• Adds mocks for the new URI patterns
• Tests it all

#497
CC @ko1ynnky I decided to go a bit further and getting very good results now. Thanks for the encouragement.

[Copilot]

Pull Request Overview

This PR refactors file handling by introducing a dedicated raw content client and updating existing resource and tool handlers to return structured text or blob resources. It also updates the server bootstrap, default toolset configuration, mocks, and tests to support the new raw client, and adds missing third-party LICENSE files and updated license listings.

Reviewed Changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
third-party/*/LICENSE	Added missing LICENSE files for vendored third-party dependencies.
third-party-licenses.{windows,linux,darwin}.md	Updated markdown lists to include new BSD-3-Clause dependencies.
pkg/raw/raw.go, pkg/raw/raw_mock.go, pkg/raw/raw_test.go	New raw package: client adapter, mocks, and tests for raw API.
pkg/github/repository_resource.go, pkg/github/repository_resource_test.go	Updated resource handler to use raw client and return resources.
pkg/github/repositories.go, pkg/github/repositories_test.go	Updated GetFileContents tool to fetch via raw client and return resource results.
pkg/github/tools.go, pkg/github/server_test.go	Injected getRawClient into default toolset and server tests.
internal/ghmcp/server.go	Configured rawURL in API host and getRawClient in server setup.
pkg/github/helper_test.go	New test helpers for extracting text and blob resources.

Comments suppressed due to low confidence (2)

pkg/raw/raw.go:22

• The SemanticSearchRequest type is unrelated to raw file handling and is unused; consider removing it to keep the package focused.

type SemanticSearchRequest struct {

pkg/github/repository_resource.go:176

• The code uses base64.StdEncoding.EncodeToString but the encoding/base64 package is not imported; add import "encoding/base64".

Blob:     base64.StdEncoding.EncodeToString(content),

[ko1ynnky]

@SamMorrowDrums
Thanks Sam! Great work taking this much further - your solution is way better than mine. Glad I could provide some encouragement to get the ball rolling!