Add Effect v4 support, Fast Refresh tooling, and revamped docs (#56)

## Summary

- Add `effect-fc-next`, a React 19 integration targeting Effect v4 beta.
- Introduce component lifecycles, scoped resources, queries, mutations, forms, lenses, views, and refreshable components.
- Add `@effect-view/vite-plugin` for Vite Fast Refresh support.
- Add an Effect v4 example application covering the new APIs.
- Expand test coverage for both the existing and next-generation packages.
- Replace the starter Docusaurus content with complete Effect View documentation while preserving the Effect v3 docs as a versioned snapshot.
- Update the landing page, navigation, package scripts, and build output.
- Extend CI with linting, tests, package builds, Docker builds, and container publishing.

## Validation

- `bun lint:tsc`
- `bun lint:biome`
- `bun test`
- `bun run build`
- `bun pack`
- Docker image build

---------

Co-authored-by: Julien Valverdé <julien.valverde@mailo.com>
Reviewed-on: Thilawyn/effect-fc#56

Dockerfile

@@ -0,0 +1,12 @@
+FROM oven/bun:1.3.12-debian@sha256:1b709c9dd883fc1af38c210f7ea5222c552a8d470ea73efbd4b8fcfee798a64b AS bun
+
+FROM node:22.21.1-trixie-slim@sha256:98e1429d1a0b99378b4de43fa385f0746fd6276faf4feeb6104d91f6bad290f9
+COPY --from=bun /usr/local/bin/bun /usr/local/bin/bunx /usr/local/bin/
+COPY . /app
+WORKDIR /app
+
+RUN bun install --frozen-lockfile && \
+    bun run build && \
+    bun clean:cache && \
+    bun clean:modules && \
+    bun install --production --frozen-lockfile