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/a3-database-crash__04-comparison.txt

@@ -0,0 +1,27 @@
+=== [4] 클라이언트가 받은 sid 가 DB 에 있는가 ===
+  클라이언트가 200 을 받은 sid: 291 건
+  DB 온라인 세션 총계: 375
+
+  --- 마지막 15건을 하나씩 조회 ---
+    TCCOYnVlN30Y2fGyJEsVJ_Lq   있음
+    vBcllIkKWovh-FXN9tSzmxAe   있음
+    eMpN_ywUdRTks9uBE9aTumPK   있음
+    aPC_T0yrlMjrlskcLAp0AvY6   있음
+    UBPxmduB-ahGHBg636sY3AEz   있음
+    HLnBloNX9R3qQJSkpOnkNqL4   있음
+    _KPJS30IAqVhkTJGHcCxKvrM   있음
+    rq3caZ9MkyMYlFSSzRjQLygD   있음
+    ivvQm70hjl55DPpF7vpYmz_E   있음
+    81mx-rmi-tAeogHx3-su3z2q   있음
+    WnvNDH93uzcz1XNFbaMSXk1A   있음
+    DXPAIhjO5sGpCUlcD8IEoS8L   있음
+    aZMvl4IwPdK-rC_7bG005Z5C   있음
+    eIuBCprfWA5x0glcgSKYrrX0   있음
+    ozES5kEeu2IFf_cfcC_jFlbF   있음
+
+  마지막 15건 중 유실: 0 건
+
+=== [5] 전체 대조 — 몇 건이나 사라졌는가 ===
+  클라이언트 성공: 291 건
+  DB 에 존재:      291 건
+  ★ 유실:          0 건