[processor/redaction] Apply blocked_values patterns in configuration order

[yamoyamoto]

Description

Apply blocked_values patterns in the order they are listed in the configuration.

Previously the compiled patterns were stored in a map and applied in Go's unspecified map iteration order, so when two patterns matched overlapping regions of the same value, the result changed from run to run. See the tracking issue for details.

makeRegexList now returns an order-preserving slice instead of a map. The other lists built by the same helper (allowed_values, blocked_key_patterns, ignored_key_patterns) are only used with any-match semantics, so this has no behavioral effect on them. No config schema change.

Note: the map implicitly deduplicated identical pattern strings; with the slice, a duplicated pattern is now applied twice. This is only observable with hash_function configured. I kept the code simple rather than deduplicating, but can add it if preferred.

Link to tracking issue

Fixes #49858

Testing

Added TestBlockedValuesAppliedInConfigOrder: two overlapping patterns against 777-7777@example.com, asserting the expected output for both orderings, on both the attribute and log body paths, repeated 10 times so a regression to nondeterministic ordering fails reliably.

Documentation

Documented the ordering behavior in the README and added a bug_fix changelog entry.

Authorship

• I, a human, wrote this pull request description myself.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: yamoyamoto / name: Tomoya Kawaguchi (bd01336)

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Status last refreshed: 2026-07-27 16:17:10 UTC.

• Status: Merged.

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[singhvibhanshu]

/workflow-approve

[singhvibhanshu]

/workflow-approve

[paulojmdias]

/workflow-approve

[singhvibhanshu]

/workflow-approve

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