Adopt agent-plugins-spec 1.0.0 (additive, no deletions)

[gjethwani-figma]

What

Adds the two spec-canonical root files defined by agent-plugins-spec 1.0.0 so spec-aware clients discover this plugin via the standard layout:

• plugin.json — conforms to plugin.schema.json 1.0.0 ($schema + name required). Mirrors the metadata already in .github/plugin/plugin.json.
• mcp.json — conforms to mcp.schema.json 1.0.0. Declares the remote Figma MCP server as type: "streamable-http" (the spec's constant) pointing at https://mcp.figma.com/mcp.

Why

Cross-company Agent Plugins spec is being announced; adopting it here is a small, structural change that unifies the plugin folder/JSON layout. The awesome-copilot marketplace listing is unaffected — it continues to resolve to this repo.

Scope — intentionally additive, nothing deleted

This PR adds two files and changes/removes nothing, so no live integration is touched:

• Bundled skills/, workflow-skills/, figma-power/ — kept.
• Per-client manifests .claude-plugin/, .cursor-plugin/, gemini-extension.json — kept.
• Existing .mcp.json — kept as-is (still type: "http" for current VS Code consumption).

Retiring the bundle and unifying the per-client manifests are deliberately left for a separate follow-up PR.

Notes

• The VS Code-specific _meta block (tool titles / icon) from .mcp.json is omitted from mcp.json: the spec's streamable-http server sets additionalProperties: false, so only type/url/headers are permitted. _meta remains in .mcp.json.
• Both files validated against the 1.0.0 schemas (required fields, allowed keys, name pattern, server type constant).

🤖 Generated with Claude Code

[digitarald]

The new plugin.json and mcp.json look schema-correct, and the immediate-child skills/ layout matches Agent Plugins 1.0. Nice to see Figma adopting the portable entrypoint.

One behavior caveat: this is not entirely additive for spec-aware VS Code versions. A root plugin.json with the Agent Plugins $schema takes precedence over legacy metadata. VS Code then reads only root mcp.json and ignores .mcp.json, so the existing VS Code-specific _meta block—including tool titles and the icon—is no longer consumed. The MCP server should continue to work, but its presentation metadata may regress.

I suggest updating the PR description to make that behavior change explicit and verifying the resulting VS Code experience. Longer term, this metadata likely belongs under the com.github.copilot client namespace once VS Code defines semantics for it; until then, there is no spec-valid place for _meta in the portable mcp.json.

Also worth documenting that workflow-skills/ is not a portable component path. Agent Plugins clients discover only immediate child skill directories under skills/, so those workflow skills remain client-specific unless they are moved or projected separately.