## Stack context
This is the second PR in the V5 documentation stack, on top of the versioned API reference.
## What and why
Add an agent-oriented V3/V4 to V5 migration guide covering document ingestion and updates, content management, search, profiles, forgetting, namespaces, organization settings, typed filters, and rollout verification. Shared snippets keep the comprehensive guide and focused topic pages consistent.
```mermaid
flowchart LR
Legacy[Legacy integration inventory] --> Mapping[Domain migration guidance]
Mapping --> V5[V5 requests and response readers]
V5 --> Verify[Side-by-side verification and rollout]
```
## Validation
- Verified all 11 migration navigation entries resolve to authored pages.
- Verified all imports across 23 migration and snippet files resolve.
- `git diff --check` passed.
- Mintlify build validation passed against the local generated V5 OpenAPI snapshot.
## Impact
Documentation only. The guide explicitly covers changed defaults, removed operations, partial failures, namespace isolation, and rollback-oriented side-by-side testing.
Keep docs asset URLs repo-root-relative and pass images as literal MDX children so Mintlify can compile them through OptimizedImage under the /docs mount.
Mintlify's official guidance says: “Image paths are root-relative from your docs repository.” It also says relative paths such as `./screenshot.png` are unsupported. See [Image embeds](https://www.mintlify.com/docs/create/image-embeds).
The existing `/images/...` paths were correct. The failure came from passing them through custom-component string props, which kept Mintlify from seeing those images during its MDX transform.
- fix hero, building-block, and Slack avatar images
- preserve Slack avatar clipping
- normalize Hermes and Company Brain icon sizing
Tested with Mintlify validation, broken-link checks, and browser checks across every changed route.
Fixes broken docs navigation and asset paths from the site audit.
- serves docs images from `/images` and adds the missing Cartesia icon
- corrects homepage, console, and LinkedIn destinations
- removes agent-only comparison headings from the web TOC
Tested with Mintlify validate and Mintlify broken-links.
