docs: repoint dead planning/specs docstring references

Six module docstrings cited planning/specs/2026-06-*.md, a directory that
no longer exists; repoint them to the living architecture/ truth home.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: lesnik512

src/httpware/_internal/observability.py

@@ -1,6 +1,6 @@
 """Observability emission helper — structured logging + opt-in OpenTelemetry span events.
 
-See planning/specs/2026-06-05-observability-design.md for the contract.
+See architecture/resilience.md (Observability section) for the contract.
 
 Logger names (``httpware.retry``, ``httpware.bulkhead``, ``httpware.circuit_breaker``,
 ``httpware.timeout``) and event names (``retry.giving_up``, ``bulkhead.rejected``,

src/httpware/client.py

@@ -1118,7 +1118,7 @@ async def stream(  # noqa: PLR0913, C901 — mirrors httpx2 per-method signature
         is closed when the context exits.
 
         Bypasses the middleware chain (no AsyncRetry, no AsyncBulkhead, no user-installed
-        middleware) for v1 — see planning/specs/2026-06-05-streaming-design.md.
+        middleware) for v1 — see architecture/client.md for the contract.
 
         Auto-raises StatusError subclasses on 4xx/5xx (NotFoundError,
         ServiceUnavailableError, etc.) — consistent with client.get()/post()/etc.

src/httpware/middleware/resilience/budget.py

@@ -1,6 +1,6 @@
 """Finagle-style token-bucket retry budget.
 
-See planning/specs/2026-06-05-retry-and-retry-budget-design.md for the contract.
+See architecture/resilience.md (Retry + RetryBudget section) for the contract.
 
 Thread-safe and asyncio-safe: all mutations go through a threading.Lock,
 which ensures no torn state across concurrent accesses. When a RetryBudget

src/httpware/middleware/resilience/bulkhead.py

@@ -1,6 +1,6 @@
 """AsyncBulkhead middleware — concurrency limiter via asyncio.Semaphore.
 
-See planning/specs/2026-06-05-bulkhead-design.md for the contract.
+See architecture/resilience.md (Bulkhead section) for the contract.
 
 The middleware owns an asyncio.Semaphore(max_concurrent). On each request,
 it acquires a slot (bounded by acquire_timeout via asyncio.timeout) and

src/httpware/middleware/resilience/circuit_breaker.py

@@ -1,6 +1,6 @@
 """CircuitBreaker + AsyncCircuitBreaker — consecutive-failure and failure-rate circuit breakers.
 
-See planning/specs/2026-06-13-circuit-breaker-and-timeout-design.md for the contract.
+See architecture/resilience.md (CircuitBreaker + AsyncTimeout section) for the contract.
 
 A counted failure is a NetworkError, an httpware TimeoutError, or a StatusError whose
 status_code is in the effective failure set (default: all 5xx). 4xx — including 429 —

src/httpware/middleware/resilience/retry.py

@@ -1,6 +1,6 @@
 """AsyncRetry + Retry middleware — automatic retry of transient failures with budget control.
 
-See planning/specs/2026-06-05-retry-and-retry-budget-design.md for the full contract.
+See architecture/resilience.md (Retry + RetryBudget section) for the full contract.
 
 Status-code retry: the client terminal raises StatusError subclasses on 4xx/5xx,
 so the retry middleware catches StatusError and inspects exc.response.status_code. The