docs: cover Foundry v1.7 Tempo, MPP, and selective follow-up gaps

[decofe]

Summary

This PR documents the most important user-facing gaps I found while reviewing the Foundry v1.7.0 release notes against the current book, with a focus on Tempo and MPP first, plus a small selective follow-up for other high-leverage v1.7.0 features.

This PR now:

• replaces the outdated foundryup -n tempo install flow with upstream v1.7.0 guidance
• adds a Tempo guide covering forge init --network tempo, foundry.toml setup, Tempo transaction flags, and Anvil usage
• adds an MPP guide covering wallet setup, HTTP 402-gated RPCs, key discovery, deposit tuning, and channel persistence
• documents the new runtime network and namespaced hardfork config in the config reference and default config page
• adds a selective follow-up for advanced invariant-testing options and debugging improvements such as forge inspect ... linearization
• exposes the new guides in the guides index and sidebar

Scope

I kept this intentionally selective.

The release notes contain many v1.7.0 changes that are already discoverable through generated CLI reference pages or are too narrow to justify guide-level documentation right now. This PR focuses on the user-facing gaps that were both:

• clearly missing from the book
• likely to block or confuse real users upgrading to v1.7.0

Audit Findings

The main gaps I found were:

• the installation docs still pointed readers to the deprecated Tempo fork instead of the main Foundry release
• the book had no narrative guide for configuring Foundry projects for Tempo, even though Tempo is upstreamed in v1.7.0
• the config reference did not explain the new network key or namespaced runtime hardfork values like tempo:T3
• the book had no page describing MPP-backed RPC endpoints, despite v1.7.0 shipping first-class 402 handling
• a few important non-Tempo additions still lacked narrative coverage, especially advanced invariant-campaign options and forge inspect ... linearization

References

• Foundry v1.7.0 release notes: https://github.com/foundry-rs/foundry/releases/tag/v1.7.0
• Tempo Foundry docs: https://docs.tempo.xyz/sdk/foundry
• Tempo MPP docs: https://docs.tempo.xyz/sdk/foundry/mpp

Validation

• NODE_OPTIONS='--max-old-space-size=4096' ./node_modules/.bin/vite build

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Project	Deployment	Actions	Updated (UTC)
foundry-docs	Ready	Preview, Comment	Apr 30, 2026 0:40am

[zerosnacks]

cc @mablr / @figtracer please have a look

[mablr]

Sgtm.

We will need to include per-test network selection logic foundry-rs/foundry#14530.

[figtracer]

lg

[zerosnacks]

We will need to include per-test network selection logic foundry-rs/foundry#14530.

Sounds good, lets do that as a follow up