docs: remove stale cmd/eyrie/ doc references (#29)

The eyrie/docs/ARCHITECTURE.md Components diagram and the README.md
build instructions both referenced a cmd/eyrie/ directory that does
not exist — eyrie is a library, not a CLI. Reword the docs to
reflect the library-only reality:

- docs/ARCHITECTURE.md: drop the 'cmd/eyrie/' tree entry, keep the
  api/openapi.yaml entry (the OpenAPI spec documents the embedded
  HTTP server in internal/api, not a standalone binary).
- README.md: replace 'go build ./cmd/eyrie' with 'go build ./...'
  to match Makefile:46 (the build target is just 'go build ./...'
  to verify the library compiles).

Author: Patel230

README.md

@@ -285,7 +285,7 @@ eyrie is part of the hawk-eco:
 ### Build & Test
 
 ```bash
-go build ./cmd/eyrie          # Build binary
+go build ./...               # Verify the library compiles
 go test -race ./...           # Run all tests with race detector
 make ci                       # Run full CI suite (lint, test, security)
 make cover                    # Generate coverage report

docs/ARCHITECTURE.md

@@ -24,8 +24,7 @@ eyrie is the LLM provider runtime for the hawk ecosystem. It sits between the ap
 
 ```
 eyrie/
-├── cmd/eyrie/               ⚡ Entry point — CLI arg parsing, server startup
-├── api/openapi.yaml         📜 REST API contract (OpenAPI 3.1)
+├── api/openapi.yaml         📜 REST API contract (OpenAPI 3.1) — embedded HTTP server surface
 ├── client/
 │   ├── client.go            🔌 Provider interface + EyrieClient factory
 │   ├── anthropic.go         🟠 Anthropic Claude provider