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>

docs/developers/guides/README.md

@@ -0,0 +1,12 @@
+# Guides
+
+Step-by-step walkthroughs for each AgentIdP workflow.
+
+| Guide | What it covers |
+|-------|----------------|
+| [Register an Agent](register-an-agent.md) | All registration fields, validation rules, common errors and fixes |
+| [Manage Credentials](manage-credentials.md) | Generate, list, rotate, and revoke credentials |
+| [Issue and Revoke Tokens](issue-and-revoke-tokens.md) | OAuth 2.0 Client Credentials flow, JWT structure, introspect, revoke |
+| [Query Audit Logs](query-audit-logs.md) | Filters, pagination, event structure, 90-day retention |
+
+All guides assume you have a running local server and a valid Bearer token. See the [Quick Start](../quick-start.md) if you haven't done that yet.