fix(repos): return a resource link for files over 1 MB in get_file_contents

[jayhemnani9910]

Summary

get_file_contents errors on every file of 1 MB or more since v1.10.0. This treats the Contents API's encoding: "none" response as "content not returned", so the existing large-file resource link is returned again.

Why

Fixes #3417

The Contents API returns files over 1 MB with "content": "" and "encoding": "none". repositoryContentBytes called GetContent() on that and failed with unsupported content encoding: none before the fileSize >= maxContentSize branch ran.

What changed

• repositoryContentBytes: an encoding: "none" response is handled like a missing content field.
• New subtest in Test_GetFileContents_ContentlessRequestCounts using the real API response shape (content: "", encoding: "none"). It fails without the fix.

MCP impact

• No tool or API changes
• Tool schema or behavior changed
  get_file_contents returns the "too large to display" message and resource link for files over 1 MB again, as in v1.9.0. No schema change.
• New tool added

Prompts tested (tool changes only)

• "Show me drivers/gpu/drm/amd/include/asic_reg/nbio/nbio_7_4_sh_mask.h in torvalds/linux" (5 MB file): now gets the download URL instead of an error.

Security / limits

• No security or limits impact
• Auth / permissions considered
• Data exposure, filtering, or token/size limits considered

Tool renaming

• I am renaming tools as part of this PR (e.g. a part of a consolidation effort)
  • I have added the new tool aliases in deprecated_tool_aliases.go
• I am not renaming tools as part of this PR

Lint & tests

• Linted locally (golangci-lint v2.14.0, the version ./script/lint pins, and gofmt -l: clean)
• Tested locally with go test ./... (30 packages ok, same as main)

Ran against the real API with v1.14.0 and with this branch: a 1.5 MB PNG and a 5 MB C header both error on v1.14.0 and return the resource link with this change. Small files and symlinked files are unchanged.

Docs

• Not needed
• Updated (README / docs / examples)

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.