docs: merge Build on Celo and Tooling into one Build tab

[GigaHierz]

Closes #2259

Stacked on #2367 (Learn tab). This branch contains that PR's commit plus one more, so the diff here shows only the Build change; merge #2367 first, without deleting its branch, and then retarget this PR to main.

"Build on Celo" and "Tooling" become one Build tab. The Tooling tab is gone. Agents and Mini Apps lead, in the order the issue asks for.

Group order

Quickstart, Agents, Mini Apps, Network info, Guides, Tools, Reference.

Group	Pages
Quickstart	Build home, quickstart, the tooling overview, migrate from Ethereum
Agents	One flat ordered list: overview, use docs with AI, ERC-8004, Self Agent ID, x402, x402 discovery, MPP, Celopedia, vibe coding, the three MCP pages, use cases, attribution tags
Mini Apps	The single MiniPay overview
Network info	Celo Sepolia, node overview, Forno, Alchemy
Guides	Farcaster, Self, local stablecoins, USA₮, SocialConnect, DeFi, the three fee-abstraction pages, scaling, Nightfall, funding
Tools	Libraries and SDKs (CLI, ContractKit), dev environments (thirdweb as one tool page), wallets, indexers, oracles, explorers, contract verification, bridges
Reference	The five contract pages and the launch checklist

Every moved page appears exactly once in the nav.

Paths

• tooling/<path> becomes build/tools/<path>, and build-on-celo/<path> becomes build/<path>, 1:1, with these overrides: build-on-celo/build-with-ai/* becomes build/agents/*, attribution-tags becomes build/agents/attribution-tags, and build-on-minipay/overview becomes build/mini-apps/overview.
• 126 files moved (125 pages and the CLI README.txt). 75 files had inbound links rewritten, including AGENTS.md (content directories and the canonical-page table), ANALYTICS.md and scripts/ (the contract generator now writes to build/tools/contracts/, and its README table is updated).
• .github/CODEOWNERS: /build-on-celo/ and /tooling/... become /build/ and /build/tools/..., keeping each team's ownership.

Redirects

• Catch-alls /build-on-celo/:slug* to /build/:slug* and /tooling/:slug* to /build/tools/:slug*, plus /build-on-celo to /build and /tooling to /build/tools/overview.
• Per-file overrides: the agent pages (/build-on-celo/build-with-ai/:slug* and the old /build/build-with-ai/:slug*), the MiniPay paths, and attribution-tags.
• Every existing redirect that pointed into the old locations now points straight at the new page, so there are no chains.
• Removed the old /build/:slug* catch-all and exact /build (they would shadow real /build/... pages) and the exact /build/build-on-socialconnect (now a real page).

Verification

$ mint broken-links --check-redirects
success no broken links found
$ bash scripts/check-orphans.sh
No orphan pages found.

• A script resolved all 190 old page URLs (every home, build-on-celo and tooling page on main) through docs.json: 0 unresolved, 0 chains.
• Under mint dev, 22 sampled old URLs redirect in one step to the new page, and 19 new URLs return 200. One bad target was found and fixed (/build-on-celo/attribution-tags was going to /build/attribution-tags; it now has its own entry). The tab bar reads Learn, Build, Contribute to Celo, Operate.

Not in this PR

• Page titles are not rewritten, so the "Build with X / Build for X" convention is not applied to titles (the epic says story: Learn tab — move home/* (plus kept L1 content) to learn/* #2258 to story: Operate tab — move infra-partners/* to operate/* and fold Specs in as a Specification section #2260 move paths and do not rewrite content).
• tooling/nodes/run-a-celo-node does not exist any more, so the agreed Operate redirect has nothing to add.
• Open PRs docs(metamask): point end users at the add-network button and the wallets page #2355 to docs: point every developer-newsletter link at one subscribe page and drop Tech Sync #2360 edit files that move here; whichever merges later will need a rebase, and git follows the renames.
• home/celo.mdx card links resolve (rewritten with the rest). llms.txt is generated from the nav, so it follows the new paths after deploy.

Blocks #2261 and #2263.

🤖 Generated with Claude Code

[palango]

The move itself looks clean. After normalising the diff against the path mapping, the only content changes are link rewrites plus the AGENTS.md, scripts README and stablecoins.json path updates. The nav page set is identical to base with no duplicates, the group order matches #2259, and CODEOWNERS carries every team over. Orphan check, mint broken-links, mint broken-links --check-redirects and mint validate all pass for me on 961edef, and every page URL from main and the base branch resolves through the new redirects without 404s or chains.

The redirects need another pass before this can merge, though.

Dropping /build/:slug* breaks old /build/... URLs that production still redirects today. They currently reach a page through /build/:slug* and then the exact /build-on-celo/... entries. With this PR, /build/build-with-ai/:slug* sends them to /build/agents/<x>, which doesn't exist, and two have no match at all. These 404 under mint dev on this branch:

• /build/build-with-ai/build-with-goat/{mint-nft-agent,send-token-agent,token-swap-agent}
• /build/build-with-ai/examples/{ai-memecoins,build-with-nebula,building_with_goat}
• /build/build-with-ai/{multi-agent-systems,resources,tools}
• /build/build-with-ai/mcp/composer-mcp
• /build/build-with-zk-identity
• /build/cel2-architecture

For example, https://docs.celo.org/build/build-with-ai/resources returns 308 to /build-on-celo/build-with-ai/resources today. Adding /build/build-with-ai/build-with-goat/:slug* and /build/build-with-ai/examples/:slug* above /build/build-with-ai/:slug*, plus exact entries for the other six, would cover them, using the same destinations the /build-on-celo/... versions already have.

Two existing wildcards are now dead because the new catch-alls sit near the top of the array, and between wildcards the first match wins. Details inline.

Smaller things. build/fund-your-project.mdx:26 still has a GitHub edit link to edit/main/build-on-celo/fund-your-project.mdx, which will 404 after merge and which broken-links doesn't check. build/agents/vibe-coding.mdx:109 still links /build/build-with-ai/mcp/index; it works through the redirect but should point at /build/agents/mcp/index. And #2259's scope includes the "Build with X / Build for X" naming convention, which this PR defers, so either open a follow-up for it or don't close #2259 from here.

One for #2367 rather than this PR: /home/:slug* sits above /home/protocol/transaction/:slug*, so the latter never fires and /home/protocol/transaction/... ends up at /learn/protocol/transaction/..., which doesn't exist (the folder is transactions).

[palango]

This now sits above /tooling/libraries-sdks/particle-network/:slug* (line 2959), and between wildcards the first match wins, so that entry never fires. /tooling/libraries-sdks/particle-network has no exact entry, so it now goes to /build/tools/libraries-sdks/particle-network, which 404s (production sends it to celo-sdks today). Move the particle-network wildcard above this line.

[palango]

Same here. /build-on-celo/build-with-ai/celina/:slug* at line 4695 is now unreachable because this wildcard matches first, so celina sub-paths go to /build/agents/celina/... and 404 (the page is at build/agents/mcp/celina). Move the celina wildcard above this one.

[palango]

Old /build/build-with-ai/* pages that no longer exist now land on /build/agents/<x> and 404: the three build-with-goat/*, the three examples/*, multi-agent-systems, resources, tools and mcp/composer-mcp. Before this PR they went through /build/:slug* to the exact /build-on-celo/... entries. Could you add /build/build-with-ai/build-with-goat/:slug* and /build/build-with-ai/examples/:slug* above this line, plus exact entries for the other four, with the same destinations as their /build-on-celo counterparts?

[palango]

Removing this catch-all also drops /build/build-with-zk-identity (should go to /build/build-with-self) and /build/cel2-architecture (should go to /learn/network/architecture). Both redirect fine in production today but 404 on this branch, so they need exact entries.