docs: update references for miden-base → protocol and miden-node → node repo renames

[BrianSeong99]

Two repos have been renamed:

• miden-base → protocol
• miden-node → node

The docs still reference the old names in ~86 files across URLs, prose, CI workflows, config, and internal links.

Scope breakdown

Area	miden-base	miden-node
Active docs (docs/)	8 files	1 file
Versioned docs	~20 files	~15 files
CI workflows	2 files (~20 lines each)	2 files (~20 lines each)
Config (docusaurus, sidebars, release-manifest)	3 files	3 files
README	1 file	1 file

Key areas

• GitHub URLs (0xMiden/miden-base → 0xMiden/protocol, 0xMiden/miden-node → 0xMiden/node)
• Internal doc links (/design/miden-base/ → /design/protocol/, /design/miden-node/ → /design/node/)
• Directory names under docs/design/ and versioned_docs/
• CI workflow env vars and checkout steps
• release-manifest.yml repo keys
• docusaurus.config.ts redirect rules
• sidebars.ts comments

Note

Versioned docs snapshots (v0.11, v0.12) may keep old names since they reflect historical state.