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/grpc-advanced-bootstrap-f04.txt

@@ -0,0 +1,15 @@
+### 17.5 P3 — `capabilitiesDraggedAlong` 은 독립성을 증명하지 않는다. 상수를 상수와 비교한다
+
+```java
+/** Always empty, and the method exists so a test can assert that rather than a comment claiming it */
+public static List<GrpcAdvancedCapability> capabilitiesDraggedAlong(GrpcAdvancedCapability promoted) {
+  if (promoted == null) throw …;
+  return List.of();
+}
+```
+
+javadoc 이 스스로 밝히듯 본문은 무조건 빈 목록이다. 그것을 단언하는 테스트는 리터럴이 리터럴임을 확인한다 — 증거를 능력마다 따로 기록했다는 §4 의 설계 속성과는 아무 연결이 없다. 설계가 무너져 `apply` 가 다른 능력의 등급을 바꾸게 되어도 이 메서드는 여전히 빈 목록을 돌려준다.
+
+**진짜 증거는 같은 테스트의 다른 줄에 있다.**
+
+```java