docs: bedroom developer documentation — complete docs/developers/ set

Adds the full bedroom-developer-docs OpenSpec change implementation:

- docs/developers/README.md — index page
- docs/developers/quick-start.md — bootstrap to working token in 7 steps
- docs/developers/concepts.md — AgentIdP, AGNTCY, lifecycle, OAuth 2.0, free tier
- docs/developers/guides/README.md — guide index
- docs/developers/guides/register-an-agent.md — all fields, validation, common errors
- docs/developers/guides/manage-credentials.md — generate, list, rotate, revoke
- docs/developers/guides/issue-and-revoke-tokens.md — OAuth 2.0 flow, introspect, revoke
- docs/developers/guides/query-audit-logs.md — filters, pagination, 90-day retention
- docs/developers/api-reference.md — all 14 endpoints, all error codes, curl examples

Also commits deferred OpenSpec housekeeping from previous session:
- Archives phase-1-mvp-implementation change to openspec/changes/archive/
- Adds bedroom-developer-docs change artifacts (30/30 tasks complete)
- Syncs 4 delta specs to openspec/specs/

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

openspec/changes/bedroom-developer-docs/specs/api-reference/spec.md

@@ -0,0 +1,50 @@
+## ADDED Requirements
+
+### Requirement: API reference exists at docs/developers/api-reference.md
+The system SHALL provide a human-readable API reference at `docs/developers/api-reference.md` covering all 14 endpoints across the four services: Agent Registry, OAuth 2.0 Token, Credential Management, and Audit Log.
+
+#### Scenario: Developer finds any endpoint within 10 seconds
+- **WHEN** the developer opens the API reference
+- **THEN** they SHALL find a table of contents at the top linking to each of the four service sections
+
+### Requirement: Every endpoint is documented with method, path, description, and auth requirements
+For each of the 14 endpoints, the reference SHALL document: HTTP method, path, one-sentence description, and whether Bearer token auth is required.
+
+#### Scenario: Developer knows which endpoints require authentication
+- **WHEN** the developer scans the reference
+- **THEN** they SHALL clearly see which endpoints require a Bearer token (all except POST /token) and which do not
+
+### Requirement: Every endpoint includes a complete curl example
+For each endpoint, the reference SHALL include at least one complete, runnable curl example with real placeholder values.
+
+#### Scenario: Developer copies a curl example and runs it
+- **WHEN** the developer copies a curl example from the reference
+- **THEN** the command SHALL be complete — no ellipses, no `...`, no missing flags — requiring only substitution of their own agentId, token, and base URL
+
+### Requirement: Every endpoint documents all request parameters and body fields
+For each endpoint that accepts a request body or query parameters, the reference SHALL list every field with: name, type, required/optional, description, and validation constraints.
+
+#### Scenario: Developer knows what fields are required for POST /agents
+- **WHEN** the developer reads the POST /agents section
+- **THEN** they SHALL see a table listing every field, its type, whether it is required, and any constraints (e.g. email format, max length)
+
+### Requirement: Every endpoint documents all response codes and response body schemas
+For each endpoint, the reference SHALL document every possible HTTP response code (2xx and 4xx/5xx) with a description and example response body.
+
+#### Scenario: Developer understands a 429 response
+- **WHEN** the developer reads the rate limit error documentation
+- **THEN** they SHALL understand what triggered it, what the X-RateLimit-* headers mean, and when they can retry
+
+### Requirement: API reference includes a base URL and versioning section
+The reference SHALL include a section at the top explaining the base URL convention, port configuration, and that all endpoints are unversioned in Phase 1.
+
+#### Scenario: Developer knows where to send requests
+- **WHEN** the developer reads the base URL section
+- **THEN** they SHALL see the default base URL (http://localhost:3000), how to change the port via environment variable, and a note that versioning will be introduced in Phase 2
+
+### Requirement: API reference includes an errors section
+The reference SHALL include a dedicated errors section listing all standard error response shapes, all custom error codes, and their HTTP status code mappings.
+
+#### Scenario: Developer handles an AgentNotFoundError
+- **WHEN** the developer reads the errors section
+- **THEN** they SHALL see the exact JSON shape of the error response, the error code string, and the HTTP status (404)