REGEX_PATTERNS static in secrets_redactor.rs increased the P50 memory usage

[ZhidongPeng]

Issue:
REGEX_PATTERNS static in secrets_redactor.rs (PR #317)

• Before PR regex perf improvements #317, Regex::new() was called on-the-fly and the compiled automaton was dropped after use.
• Now 17 compiled regex::Regex objects live permanently, including several extremely complex patterns:

1. "(?i)((app(lication)?|client|api)[_ \-]?(se?cre?t|key(url)?)|(refresh|twilio...)..."
2. "(?-i)eyJ(?i)[a-z0-9\-_%]+\.(?-i)eyJ"
3. The 500+ character Azure Storage and auth header patterns

The regex crate compiles each pattern to an NFA and pre-builds DFA transition tables. For complex patterns with deep alternation and lookaheads, this can easily consume hundreds of KB each. 17 patterns × ~200–400 KB each = estimated 3–5 MB permanently resident.

Fix:
Part 1 — Eliminate 6 compiled Regex objects entirely
The patterns pwd=[^;], password=[^;], AccountKey=[^;], PrimaryKey=[^;], SecondaryKey=[^;], and sig=[^&] are all structurally identical: match a fixed literal prefix, then capture everything up to a single stop character. The new redact_prefixed() helper does this with plain str::find — zero compiled automaton, zero regex heap.

Memory saved: ~6 compiled Regex objects removed (the simple ones each cost tens of KB; gone completely).

Part 2 — Per-indicator LazyLock dispatch for the 11 complex patterns
Previously: any indicator (e.g., the word "key" in a path like "key_keeper") triggered all 17 patterns to run.
Now: each pattern has its own static LazyLock and only runs when its own specific indicator is present.