Rebuild TruthGate documentation

[magiccodingman]

What changed

This PR rebuilds TruthGate's public documentation around the current Docker appliance and current source behavior.

README

• replaces the old marketing-heavy README with a substantial product and architecture overview
• explains why TruthGate exists and how it fits around Kubo
• covers the complete feature surface at a useful high level:
  • role-based accounts and session login
  • generated first-run administrator credentials
  • API-key creation, hashing, revocation, and usage
  • authenticated access to the native IPFS WebUI
  • protected /ipfs/, /ipns/, /api/v0/, and WebUI routing
  • CID pin management
  • watched IPNS pinning and retention behavior
  • TGP
  • static-site and SPA publishing
  • domains, mapped-host routing, automatic TLS, and ACME
  • public deployment metadata
  • Docker packaging, AMD64/ARM64 images, persistence, Kubo migrations, and diagnostics
  • Kubo server defaults and rate protection
• adds product screenshots from content/images/demo/ next to the features they demonstrate
• removes the old organization association and vague security/legal guarantees
• links directly into the repository documentation and Docker Hub

Documentation structure

Adds a versioned docs/ tree with an index.md in every directory:

• docs/setup/ — installation, first run, networking, configuration, storage, updates, and legacy migration
• docs/concepts/ — architecture, request routing, pinning/IPNS/publishing, security boundaries, and persistence
• docs/api/ — authentication, Kubo proxy, domain metadata, errors, and rate limits
• docs/tgp/ — rationale, normative v1 specification, client behavior, publisher workflow, gateway behavior, legal limitations, notice template, and FAQ
• docs/reference/ — environment variables, ports and paths, Kubo defaults, image tags, and rate-limit defaults
• docs/developer/ — Compose model, Rider setup, Visual Studio placeholder, testing, and documentation contribution rules
• top-level site-publishing and troubleshooting guides

Developer workflow

Documents the tested development model:

docker compose -f compose.yaml -f compose.dev.yaml up --build

The production definition is intentionally first and the development file is an override. New production requirements belong in compose.yaml; compose.dev.yaml should contain only development differences.

The Rider guide documents:

• service truthgate
• Compose files ./compose.yaml; ./compose.dev.yaml; in that order
• generated-password retrieval
• hot reload and source mounting
• avoiding a second local Kubo/IPFS Desktop process on the default swarm ports

The Visual Studio page is explicitly marked as not yet verified rather than inventing IDE instructions.

TGP

TGP is now documented as a real protocol instead of being mixed into product copy.

• wire protocol version remains integer 1
• specification revisions are distinguished from the wire value
• tgp.json fields, client rules, caching, failure behavior, schema, and conformance are defined
• publisher and gateway recommendations are separated from the normative specification
• legal documentation clearly states that TGP is an operational pointer/removal workflow, not legal immunity, global deletion, or control over third-party copies

Compatibility and validation

• retains DOCKER.md as a short compatibility page pointing to the new versioned guides
• adds scripts/check-docs.py
• adds a documentation workflow that validates:
  • every docs directory has index.md
  • repository-relative Markdown links resolve
  • README links to docs/index.md
  • stale organization, shared-password, bare-metal runner, and cannot-be-Dockerized language does not return

Source alignment

Exact values were reconciled against current master, including:

• Docker and Compose layout
• generated first-run password behavior
• Kubo v0.42.0 and .NET 10 build defaults
• persistent paths
• loopback Kubo RPC and gateway listeners
• production and development ports
• Kubo server policy defaults
• current public and gateway rate-limit defaults
• Blazor Server/WebAssembly hosting and bootstrap requirements

Planned or unverified behavior is labeled rather than written as implemented fact.

Validation

Local documentation validation passed for 45 Markdown files:

Documentation validation passed for 45 Markdown files.

This PR intentionally changes documentation and documentation CI only. It does not change the TruthGate application, Docker runtime behavior, Compose definitions, or release pipeline.