fix: harden Anthropic proxy shape guard

CHANGELOG.md

@@ -7,6 +7,22 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Mutation authorization now comes from intrinsic secret format, exact known-value
+  evidence, or an operator custom rule. Severity and request-field context affect
+  advisory reporting only; format-only DSN/JDBC and generic credential matches remain
+  visible without being rewritten.
+- The Anthropic request scanner now covers tool contracts, input examples, message text,
+  tool inputs/results, and stop sequences, and rejects malformed tool/stop containers.
+- Proxy replacement is documented as one-way. Reversible local restoration remains an
+  MCP read/write capability.
+
+### Fixed
+
+- Azure Storage connection-string detection no longer consumes bytes following the
+  base64 `AccountKey` value.
+
 ## [0.29.0] - 2026-07-12
 
 ### Added

Sources/Pastewatch/ClipboardMonitor.swift

@@ -117,18 +117,28 @@ final class ClipboardMonitor: ObservableObject {
         guard config.enabled else { return }
 
         // Scan for sensitive data
-        let matches = DetectionRules.scan(content, config: config)
+        let matches = DetectionRules.scan(
+            content,
+            config: config,
+            customRules: CustomRule.compileValid(config.customRules)
+        )
 
         // No matches — nothing to do
-        guard !matches.isEmpty else { return }
+        let outcome = applyAuthorizedMutations(
+            to: content,
+            matches: matches,
+            site: .clipboard,
+            minAdvisorySeverity: .low
+        )
+        guard !outcome.mutated.isEmpty else { return }
 
         // Obfuscate and replace clipboard content
-        let obfuscatedContent = Obfuscator.obfuscate(content, matches: matches)
+        let obfuscatedContent = outcome.text
 
         // Create scan result
         let result = ScanResult(
             originalContent: content,
-            matches: matches,
+            matches: outcome.mutated,
             obfuscatedContent: obfuscatedContent,
             timestamp: Date()
         )
@@ -143,7 +153,7 @@ final class ClipboardMonitor: ObservableObject {
         // Update state
         DispatchQueue.main.async { [weak self] in
             self?.lastScanResult = result
-            self?.sessionObfuscationCount += matches.count
+            self?.sessionObfuscationCount += outcome.mutated.count
             self?.onObfuscation?(result)
         }
     }
@@ -154,13 +164,22 @@ final class ClipboardMonitor: ObservableObject {
         guard let content = NSPasteboard.general.string(forType: .string) else { return nil }
         guard !content.isEmpty else { return nil }
 
-        let matches = DetectionRules.scan(content, config: config)
-        let obfuscatedContent = Obfuscator.obfuscate(content, matches: matches)
+        let matches = DetectionRules.scan(
+            content,
+            config: config,
+            customRules: CustomRule.compileValid(config.customRules)
+        )
+        let outcome = applyAuthorizedMutations(
+            to: content,
+            matches: matches,
+            site: .clipboard,
+            minAdvisorySeverity: .low
+        )
 
         return ScanResult(
             originalContent: content,
-            matches: matches,
-            obfuscatedContent: obfuscatedContent,
+            matches: outcome.mutated,
+            obfuscatedContent: outcome.text,
             timestamp: Date()
         )
     }

Sources/PastewatchCLI/GuardCommand.swift

@@ -40,7 +40,7 @@ struct Guard: ParsableCommand {
             $0.effectiveSeverity >= failOnSeverity
         }
         // WO-138: JSON output must preserve command context without echoing inline credential values.
-        let redactedCommand = Obfuscator.obfuscate(command, matches: commandDisplayMatches)
+        let redactedCommand = Obfuscator.redactForDisplay(command, matches: commandDisplayMatches)
 
         if !commandFiltered.isEmpty {
             shouldBlock = true