fix(redaction): make Authorization-header redaction linear too

_REDACT_AUTH_HEADER matched the value's opening as `\s*["\']?\s*`: two
`\s*` separated only by an optional quote. With no quote, a whitespace
run could be split between them in every possible way, and when no
credential followed (end of text, or `,` `"` `<` ...) the engine tried
them all before giving up: quadratic, 8s for `authorization:` and 20k
spaces, 17s with `Proxy-Authorization:` (tried again at the inner
`authorization`). Same stall as the URL pattern: re.sub holds the GIL,
and the display service redacts everything it publishes.

The quote and the whitespace after it are now one optional unit,
`\s*(?:["\']\s*)?`, which matches the same strings with only one way to
split them. Output is identical to the old pattern on 300k fuzzed
inputs; 20k spaces now take ~1.6ms. A scan of all three redaction
patterns over prefix/run/suffix shapes finds none left that scales
superlinearly.

test/test_redaction.py pins exact output for quoted, tabbed, multi-line
and credential-less headers, and bounds header + 20k whitespace at 1s;
against the previous pattern those fail at 8-17s each.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KMXdS2S4NXTJ8ET96GymhK

src/redaction.py

@@ -24,8 +24,13 @@ _REDACT_CREDENTIAL = re.compile(
 # silently leak the ones nobody thought of. Not covered by the generic pattern
 # above, whose value part stops at whitespace and so would keep the credential
 # once a space follows the scheme.
+#
+# The opening quote and the whitespace after it are one optional unit. Written
+# `\s*["\']?\s*`, a whitespace run with no quote in it could be split between
+# the two `\s*` in every possible way, and a header with no credential after
+# it tried them all: quadratic, 8s for 20k spaces.
 _REDACT_AUTH_HEADER = re.compile(
-    r'((?:proxy-)?authorization["\']?\s*[=:]\s*["\']?\s*'
+    r'((?:proxy-)?authorization["\']?\s*[=:]\s*(?:["\']\s*)?'
     r'(?:[A-Za-z][\w.+-]*[ \t]+)?)'          # optional scheme name, kept
     r'([^\s,"\'<>}]+)',                       # the credential, redacted
     re.IGNORECASE,