fix: proxy/attempts truthiness bugs, stale text() cache, preview cookie order (v0.1.9)

_get_proxy() and request() checked proxies/proxy with truthiness instead of
is None, so a per-call proxies={} silently fell back to session proxies, and a
native proxy= kwarg was clobbered by resolved session proxies (unmasking the
caller's real IP) instead of raising on conflicting sources. Response.text()
cached the first decode regardless of a later explicit encoding= argument.
preview() computed the Cookie header from the pre-rewrite url instead of the
rewritten one actually used by request(). request_with_retries(attempts=0)
became DEFAULT_ATTEMPTS via truthiness instead of flooring to 1.

Also compresses docstrings/comments across the module (no behavior change).

Signed-off-by: disqualifier <dev@disqualifier.me>

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "aioweb"
-version = "0.1.8"
+version = "0.1.9"
 description = "Async HTTP session wrapper over aiohttp — proxies, header overwrites, retries, previews. Config-free, installable."
 requires-python = ">=3.10"
 dependencies = [