Default to consolidated actions/projects toolsets and add hold back flag

[mattdholloway]

Summary

This pull request updates the feature flag logic for both GitHub Actions and Projects tools, introducing new "holdback" feature flags to control the use of consolidated versus individual tools. The legacy consolidated feature flags are now deprecated and only kept for documentation, while the new holdback flags actively control tool availability. The changes ensure that enabling a holdback flag reverts to individual tools, and the consolidated tools are now enabled by default unless the holdback flag is set.

Why

Fixes #

What changed

MCP impact

• No tool or API changes
• Tool schema or behavior changed
• New tool added

Prompts tested (tool changes only)

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

Note: if you're renaming tools, you must add the tool aliases. For more information on how to do so, please refer to the official docs.

Lint & tests

• Linted locally with ./script/lint
• Tested locally with ./script/test

Docs

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

[Copilot]

Pull request overview

This PR inverts the feature flag behavior for consolidated actions and projects toolsets, making them the default instead of opt-in. It introduces new "holdback" feature flags that allow reverting to individual tools when needed.

Changes:

• Introduces FeatureFlagHoldbackConsolidatedActions and FeatureFlagHoldbackConsolidatedProjects as replacement flags
• Swaps FeatureFlagEnable and FeatureFlagDisable assignments across all actions and projects tools to make consolidated tools the default
• Marks legacy FeatureFlagConsolidatedActions and FeatureFlagConsolidatedProjects constants as deprecated

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
pkg/github/actions.go	Introduces holdback flag and inverts feature flag logic for 15 individual actions tools (now enabled via holdback flag) and 4 consolidated actions tools (now disabled via holdback flag)
pkg/github/projects.go	Introduces holdback flag and inverts feature flag logic for 9 individual projects tools (now enabled via holdback flag) and 3 consolidated projects tools (now disabled via holdback flag)

[Copilot]

The legacy feature flag constant is marked as deprecated but is still exported and defined. Since this is used as a library by the remote server, consider whether this constant should remain exported or if it can be removed entirely. If it's still referenced elsewhere in the remote server codebase, keeping it is correct. Otherwise, consider removing it in a follow-up PR to reduce API surface.

Suggested change

	// FeatureFlagConsolidatedProjects is the legacy feature flag (deprecated, no longer used).
	// Kept for documentation purposes only.
	const FeatureFlagConsolidatedProjects = "remote_mcp_consolidated_projects"