fix(showcase/dashboard): pass maxDepth to DepthChip so D5 cells aren't all red

The matrix chips were hard-coded red at D5 because parity-matrix and
cell-matrix passed `regression={depth.isRegression}` to DepthChip but
never `maxDepth`. DepthChip short-circuits to red when `regression` is
true, regardless of depth. Since `isRegression` was redefined as
`achieved < maxPossible` and `computeMaxPossible` returns 6 whenever a
D5 mapping exists, every D5 cell without a green D6 probe (the common
case — D6 probes are rare) ended up red.

Pass `maxDepth={depth.maxPossible}` and drop the `regression` prop. This
re-engages the chip's intended graduated coloring: green at ceiling,
amber 1-2 below, red 3+ below. The `isRegression` field is still used
by the cell-matrix `filter="regressions"` row filter — that's unchanged.

Author: AlemTuzlak

showcase/shell-dashboard/src/components/cell-matrix.tsx

@@ -182,7 +182,7 @@ function CategorySection({
                     <DepthChip
                       depth={depth.achieved}
                       status={cellStatus}
-                      regression={depth.isRegression}
+                      maxDepth={depth.maxPossible}
                     />
                   </button>
                   {isSelected && (

showcase/shell-dashboard/src/components/parity-matrix.tsx

@@ -139,7 +139,7 @@ function ParityCategorySection({
                 <DepthChip
                   depth={refDepth.achieved}
                   status={refStatus}
-                  regression={refDepth.isRegression}
+                  maxDepth={refDepth.maxPossible}
                 />
               </td>
               {nonRefIntegrations.map((int) => {
@@ -164,7 +164,7 @@ function ParityCategorySection({
                     <DepthChip
                       depth={depth.achieved}
                       status={cellStatus}
-                      regression={depth.isRegression}
+                      maxDepth={depth.maxPossible}
                     />
                   </td>
                 );