docs: document devup_visual_compare and devup_feature_trace in the tool inventory

[owjs3901]

The README said the server has seven tools and listed seven. It registers nine. devup_visual_compare and devup_feature_trace shipped without ever being written down.

That matters more than a stale number: the README states outright that it, together with the schemas the server publishes, is the authority on the current tool list - docs/superpowers/ is explicitly described as a record of its own moment rather than current API documentation. So the one document a caller is told to trust was the one omitting two tools.

What changed

• The count line now reads four Figma tools and five project tools, nine in total.
• Both tools are added to the top inventory with their real contracts.
• Each gets a detail section under 프로젝트 쪽 도구, which previously described three of the five.

The wording is taken from the tool descriptions the server actually publishes, not written fresh, so the README and the schema say the same thing:

• devup_visual_compare - never renders, never launches a browser, never runs a command; the consumer produces actual.png and this compares pixels in pure Rust. An absent, incomplete or invalid renderer environment manifest yields inconclusive even when visual.passed is true.
• devup_feature_trace - starts only from explicit anchors and refuses anchorless prose. Hops are evidence-backed or UNVERIFIED; requirement/acceptanceCriteria are echoed without interpretation; static parsing never proves runtime behaviour.

Documentation only - no crate changed, so no changepack.