test(sprint-11): centralize JaCoCo coverage rules and add bank import + finance test coverage

- pom.xml: introduce risk-tiered JaCoCo rules in parent POM
  - bundle: 80% line coverage
  - bankimport/finance packages: 90% (highest precision)
  - api.security: 85%
  - scheduler/notification: 70%
  - exclude entity/enums/dto/config from coverage measurement
  - add Surefire 3.5.2 plugin management
- cannamanage-service/pom.xml: remove obsolete module-local ComplianceService=100% rule
  (subsumed by parent package rules), add explicit jackson-databind dep so
  ByteBuddy can mock AuditService.METADATA_MAPPER
- Add AbstractServiceTest base class for service-layer tests
- Add FinanceServiceTest
- Add bankimport test suite:
  - Mt940ParserTest with malformed input fixtures
    (encoding, overflow, truncated, generic)
  - PaymentMatchingServiceTest with ParsedTransactionBuilder helper
  - CAMT.053 / Sparkasse MT940 sample fixtures
  - XXE attack fixtures (billion-laughs, SSRF, generic)
- docs/sprint-11/: analysis, plan, plan-review, testplan

cannamanage-service/src/test/resources/bankimport/xxe-billion-laughs.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE lolz [
+  <!ENTITY lol "lol">
+  <!ENTITY lol2 "&lol;&lol;&lol;&lol;&lol;&lol;&lol;&lol;&lol;&lol;">
+  <!ENTITY lol3 "&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;">
+  <!ENTITY lol4 "&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;">
+  <!ENTITY lol5 "&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;">
+]>
+<Document xmlns="urn:iso:std:iso:20022:tech:xsd:camt.053.001.08">
+  <BkToCstmrStmt>
+    <Stmt>
+      <Id>&lol5;</Id>
+    </Stmt>
+  </BkToCstmrStmt>
+</Document>