fix(contracts) : hide contract phases entirely before RTT_START_DATE

EmployeeContractPhaseResolver now accepts the data-start date and filters
out phases whose endDate is strictly before it. No work-hour or absence
data exists before the application launch date, so legacy contract
periods that ended before that date would surface meaningless RTT/CP
figures in the phase picker.

For employees who joined long before the software (typical legacy 35h
contracts, in production since 2014), only the current phase remains
visible — which also collapses the picker (threshold ≥ 2 phases).

The Employee entity reads RTT_START_DATE from $_SERVER/$_ENV directly
since it has no DI. The resolver service is wired via services.yaml.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/Service/Contracts/EmployeeContractPhaseResolver.php

@@ -12,6 +12,21 @@ use LogicException;
 
 final readonly class EmployeeContractPhaseResolver
 {
+    private ?DateTimeImmutable $dataStartDate;
+
+    public function __construct(string $dataStartDate = '')
+    {
+        $trimmed = trim($dataStartDate);
+        if ('' === $trimmed) {
+            $this->dataStartDate = null;
+
+            return;
+        }
+
+        $parsed              = DateTimeImmutable::createFromFormat('!Y-m-d', $trimmed);
+        $this->dataStartDate = $parsed instanceof DateTimeImmutable ? $parsed : null;
+    }
+
     /**
      * @return list<ContractPhase>
      */
@@ -42,6 +57,17 @@ final readonly class EmployeeContractPhaseResolver
             $phases[] = $this->buildPhase($group, $today);
         }
 
+        // Hide phases entirely before the application's data start date: no usable
+        // work-hour or absence data exists before that date, so exposing them would
+        // confuse HR (e.g. legacy contract periods predating the software launch).
+        if (null !== $this->dataStartDate) {
+            $dataStart = $this->dataStartDate;
+            $phases    = array_values(array_filter(
+                $phases,
+                static fn (ContractPhase $phase): bool => null === $phase->endDate || $phase->endDate >= $dataStart,
+            ));
+        }
+
         // Most recent first.
         return array_reverse($phases);
     }