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/a06-f003-change-streams-true.txt

@@ -0,0 +1,43 @@
+# 컴팩트 생성자가 네 입력을 세 방식으로 처리한다
+  public MongoPlatformSettings {
+    // Absent rather than empty is the normal case: a deployment that has opted the module in but
+    // configured no platform profile yet must still start, so binding treats "no profiles" as an
+    // empty map instead of a binding failure.
+    profiles = profiles == null ? Map.of() : Map.copyOf(profiles);
+    // Experimental, and therefore not a switch (MNG-INT-003). The driver-side source — watch,
+    // resumeAfter/startAfter, cursor lifetime, reconnection — is not shipped; what exists is policy
+    // and value objects that do not add up to a running consumer. Accepting the flag and ignoring
+    // it
+    // would leave an operator believing it took effect, so the value is refused rather than stored:
+    // zero beans, zero threads, and a `true` that cannot be honoured never becomes one that looks
+    // honoured.
+    changeStreams = false;
+    // Absent means the platform default, and a negative count is refused rather than clamped: a
+    // requirement of -1 is not a lenient requirement, it is a typo, and reading it as "no
+    // secondaries needed" is how a health view comes to report a cluster it never checked.
+    if (requiredSecondaries == null) {
+      requiredSecondaries = DEFAULT_REQUIRED_SECONDARIES;
+    }
+    if (requiredSecondaries < 0) {
+      throw MongoOperationRejectedException.of(
+          "config.secondaries",
+          "the required secondary count must not be negative; " + requiredSecondaries + " is");
+    }
+
+# 시작 검증기의 변경 스트림 분기
+104:    if (changeStreamsEnabled && !capabilities.isStable(MongoCapability.CHANGE_STREAM)) {
+105-      throw MongoOperationRejectedException.of(
+106-          "startup.capability",
+
+#   그 분기가 내는 문장이 저장소에 나오는 곳 전수
+…/autoconfigure/MongoStartupValidator.java:107:          "change streams are enabled but unavailable here: "
+
+# changeStreams 라는 이름이 나오는 곳 전수 (다른 타입의 동명 정적 팩터리 포함)
+test/java/dev/caskeleton/adapter/outbound/mongo/autoconfigure/MongoStartupValidationTest.java:63:    assertThat(MongoPlatformSettings.empty().changeStreams())
+test/java/dev/caskeleton/adapter/outbound/mongo/autoconfigure/MongoStartupValidationTest.java:76:    assertThat(asked.changeStreams())
+test/java/dev/caskeleton/adapter/outbound/mongo/api/profile/MongoRuntimeProfileTest.java:66:    assertThatThrownBy(() -> standalone.require(MongoTopologyRequirement.changeStreams()))
+main/java/dev/caskeleton/adapter/outbound/mongo/autoconfigure/MongoPlatformAutoConfiguration.java:363:              properties.changeStreams(),
+
+# MongoStartupValidator 를 만드는 곳 전수
+test/java/dev/caskeleton/adapter/outbound/mongo/autoconfigure/MongoStartupValidatorTest.java:143:    return new MongoStartupValidator(
+main/java/dev/caskeleton/adapter/outbound/mongo/autoconfigure/MongoPlatformAutoConfiguration.java:354:      new MongoStartupValidator(