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/keycloak-session-store/final/evidence/raw/b5-redis-loss__04-persistence.txt

@@ -0,0 +1,39 @@
+=== 복구 ===
+deployment.apps/redis scaled
+deployment "redis" successfully rolled out
+  /actuator/health       HTTP 200
+  /bff/token-boundary    HTTP 302
+  BFF 재시작 필요했나: 0,0 회 재시작
+
+=== ② 영속화 — 지금 설정으로 재시작하면 무엇이 남는가 ===
+  키 심음: before-restart
+  dbsize: 4
+
+  --- AOF 를 켜고 다시 심는다 (영속화가 켜져 있으면 살아남는가) ---
+    appendonly	yes
+    total 12
+    drwxr-xr-x    3 redis    redis         4096 Sep  4 05:26 .
+    drwxr-xr-x    1 root     root          4096 Sep  4 05:26 ..
+    drwx------    2 redis    redis         4096 Sep  4 05:26 appendonlydir
+
+  --- 파드를 지운다 ---
+deployment "redis" successfully rolled out
+  재기동 후:
+    dbsize:    0
+    b5:probe   
+    b5:aof     
+    appendonly no
+persistentvolumeclaim/redis-data created
+deployment.apps/redis configured
+deployment "redis" successfully rolled out
+
+=== 영속 볼륨 위에서 다시 시험 ===
+  appendonly	yes
+  키 심음: written-on-pvc
+sed: -e expression #1, char 8: unknown option to 's'
+
+  --- 파드를 지운다 ---
+deployment "redis" successfully rolled out
+  재기동 후:
+    dbsize:  1
+    b5:pvc   written-on-pvc