## Why

SentryAgent.ai AgentIdP Phase 1 MVP is fully implemented, tested, and live — but there is zero human-readable documentation for the developers we are building this for. A bedroom developer landing on this repo today cannot register their first agent without reading raw OpenAPI YAML or diving into source code. We fix that now.

## What Changes

- New `docs/developers/` folder containing a complete, self-contained documentation set for bedroom developers
- Quick-start guide: first agent registered and authenticated in under 5 minutes
- Core concepts doc: plain-English explanation of AgentIdP, AGNTCY alignment, and the agent identity model
- Step-by-step guides: agent registration, credential management, token issuance, audit log queries
- Human-friendly API reference: every endpoint documented with real curl examples and response samples
- FAQ: common errors, gotchas, and free-tier limits explained
- All docs written for a bedroom developer audience — no enterprise jargon, no assumed knowledge

## Capabilities

### New Capabilities

- `quick-start`: 5-minute guide from zero to first authenticated agent request — install, register, credential, token, done
- `core-concepts`: Plain-English explanation of what AgentIdP is, how it relates to AGNTCY, the agent identity lifecycle, and why it matters
- `developer-guides`: Step-by-step tutorials for the four core workflows: registering an agent, managing credentials, issuing and revoking tokens, querying the audit log
- `api-reference`: Human-friendly API reference covering all 14 endpoints with real examples, field descriptions, error codes, and rate limit notes

### Modified Capabilities

*(none — this change introduces documentation only; no existing API specs are modified)*

## Impact

- New folder: `docs/developers/` (7 markdown files)
- No code changes — documentation only
- No new dependencies
- No API changes
- Existing `docs/openapi/` specs are reference material for the Technical Writer but are not modified
