docs: document the TypeScript SDK and refresh the dApp build guide

[netsirius]

Summary

The developer docs under /build/manual/ predated the published TypeScript SDK
(@freenetorg/freenet-stdlib) and the current freenet-agent-skills dApp workflow. They pinned an
old crate version, used the retired freenet publish contract flow, documented an in-repo SDK build
that no longer exists, and never described the npm SDK or the TypeScript + Vite path.

This PR brings the developer docs in line with the current SDK and reference app (Raven), adds a
dedicated TypeScript SDK reference, and restructures the manual so the client SDKs are a first-class
section separate from contract authoring.

Closes #59

What changed

• New page: build/manual/typescript-sdk.md documents FreenetWsApi, ResponseHandler, the
  request/response classes, ContractKey/containers, the UpdateData union, delegate messaging,
  and streaming. Includes a Request ordering section for the get() FIFO hazard.
• Manual restructure: new Client SDKs section (TypeScript SDK + Rust/Dioxus client) in the
  TOC, separate from the Rust contract-authoring docs, with reciprocal cross-links.
• components/ui.md: documents the SDK end to end (npm install, WebSocket URL from
  location.host, the promise API, Vite base: "./", CSP notes).
• tutorial.md: stops hardcoding the freenet-stdlib version (recommends cargo add), adds the
  fdev prerequisite, fixes contract publishing to fdev publish ... contract --state, and adds the
  TypeScript + Vite UI path alongside Dioxus.
• example-app.md: rewritten from the broken legacy page to the current examples (freenet-ping,
  Raven, River) with the real toolchain.
• Raven rename: all freenet-microblogging references now point to Raven
  (https://github.com/freenet/raven) and present it as the TypeScript + Vite reference app.
• Fixes: correct plugin install (freenet@freenet-agent-skills) and skill label
  (dapp-builder) in build/_index.md; Vite + fdev publish --webapp-archive note and [webapp]
  anchor fix in manifest.md; localhost + /v1/ container URL in glossary.md; corrected publish
  command in docker.md; em-dashes removed per the site style.

How it was validated

• Cross-checked every API name, command, port, and code sample against the SDK source
  (freenet-stdlib/typescript: websocket-interface.ts, streaming.ts) and the
  freenet-agent-skills dapp-builder workflow.
• Cross-checked the examples against the Raven reference app's real code
  (web/src/freenet-api.ts, web/vite.config.ts, Makefile.toml). This surfaced and corrected
  three issues: the get() request-ordering hazard, the ContractKey both-parts caveat, and an
  over-strict CSP/CDN claim.
• Versions confirmed against the registries (crates.io, npm); the docs use cargo add / npm install rather than hardcoded versions.