docs(keycloak-session-store): import the session-storage lab as a new project

The keycloak project ended with four open questions that design could not
settle. A two-VM lab was built to answer them by measurement, and this is
that material: 26 experiments, 125 raw command outputs, 22 browser captures.

Follows the import procedure in README.md.

  source/     the originating repository verbatim — 78 documents, 28 SVGs,
              8 manifests, plus .source-revision recording the commit
  final/      the SSOT
    document.md   729 lines written from the 29 experiment documents, not
                  concatenated: what was predicted, what was measured, and
                  where the measurement itself was wrong
    evidence/raw    125 outputs, flattened to <experiment>__<file> because
                    the originals collided (01-baseline.txt appeared three
                    times) and the audit only globs the top level
    evidence/meta   one per raw file; command and exitCode are null and the
                    README says why rather than inventing them
    evidence/browser  22 captures
    assets/       three diagrams through techviz
    .techviz/     their VizSpecs

A separate project rather than an addition to keycloak: the B-layer answers
that project's four questions, but the A, C and D layers are about cluster
failure, SSO and operations, and one document.md should hold one subject.
The four question records there can point here through 관계.

Recorded rather than papered over: only three of the 28 diagrams were
remade. The repository forbids hand-drawn SVG and forbids titles inside the
canvas; all 28 originals carry both, so converting them is redrawing, not
reformatting. They stay in source/ and the gap is written into the document.

verify-pipeline.py passes. audit-records.py reports no issues.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/clean-architecture-backend-template/final/evidence/raw/a05-f006-stable.txt

@@ -0,0 +1,56 @@
+# 능력 리포트가 이 능력에 매긴 등급
+JpaPlatformAutoConfiguration.java:57:        CapabilitySupport.stable(JpaCapability.COMPLETION_EVIDENCE),
+JpaCapability.java:16:  COMPLETION_EVIDENCE("transaction.completion-evidence"),
+
+# 매니저의 javadoc 이 주장하는 것
+11:/**
+12: * A {@link JpaTransactionManager} that records how far each transaction got, so a commit failure
+13: * can be classified as "rolled back" or "outcome unknown" instead of guessed (design §17.2).
+14: *
+15: * <p>The phase is marked {@link TransactionCompletionEvidence#COMMITTING} immediately before the
+16: * provider commit and never after. That ordering is the whole mechanism: if the JVM, the network,
+17: * or the server dies inside {@code super.doCommit}, the last thing written is "we asked, we do not
+18: * know", which is exactly the state that must not be mistaken for a rollback.
+19: *
+20: * <p>Evidence is cleared on every path — commit success, commit failure, rollback, and cleanup. A
+21: * frame left behind on a pooled thread would attach this transaction's phase to the next unrelated
+22: * unit of work that thread picks up.
+23: */
+# 같은 파일의 코드가 하는 것
+49:  @Override
+50:  protected void doCommit(DefaultTransactionStatus status) {
+51:    TransactionEvidenceContext.mark(TransactionCompletionEvidence.COMMITTING);
+52:    try {
+53:      super.doCommit(status);
+54:      TransactionEvidenceContext.mark(TransactionCompletionEvidence.COMMITTED);
+55:    } catch (RuntimeException failure) {
+56:      TransactionEvidenceContext.mark(TransactionCompletionEvidence.UNKNOWN);
+57:      throw classifier.translateCommitFailure(failure);
+58:    } finally {
+59:      // Deliberately not cleared here. The executor's scope owns the frame's lifetime; a second
+60:      // owner popping was how an inner REQUIRES_NEW transaction deleted its outer frame.
+61:    }
+62:  }
+63:
+64:  @Override
+65:  protected void doRollback(DefaultTransactionStatus status) {
+66:    try {
+67:      super.doRollback(status);
+68:      TransactionEvidenceContext.mark(TransactionCompletionEvidence.ROLLED_BACK);
+69:    } finally {
+70:      // Deliberately not cleared here. The executor's scope owns the frame's lifetime; a second
+71:      // owner popping was how an inner REQUIRES_NEW transaction deleted its outer frame.
+72:    }
+73:  }
+
+# 그 매니저를 만드는 코드
+app-bootstrap/src/main/java/dev/caskeleton/bootstrap/autoconfigure/jpa/JpaTransactionAutoConfiguration.java:55:   * EvidenceAwareJpaTransactionManager.standard(entityManagerFactory, clock)}. The composition root
+adapter/outbound/persistence-jpa/src/main/java/dev/caskeleton/adapter/outbound/persistence/transaction/EvidenceAwareJpaTransactionManager.java:39:    return new EvidenceAwareJpaTransactionManager(
+#   자기 파일과 javadoc 을 뺀 생성 지점: 0
+#   FQCN 이 설정 리소스에 등장하는 곳: 0
+#   그 클래스를 상속하는 코드: 0
+
+# 트랜잭션 매니저 빈을 등록하는 코드 (애너테이션 다음 여섯 줄까지 본다)
+#   main: 0
+#   test: 1
+JpaPlatformRuntimeAutoConfigurationTest.java-257-    PlatformTransactionManager transactionManager() {