fix(process): retain native ownership evidence through cleanup

Keep a run-scoped evidence owner from acquisition through settlement and
cleanup retry. Bind token observations to native generations and retain
related generations and unresolved identity lookups across table omissions,
reparenting and process-group changes without treating PID hints as authority.

Use native effective UID facts for withholding decisions, corroborate Linux
procfs absence, and share the Linux stat parser with sampling and debugger
identity checks. Signal only after current token and group revalidation.
Complete swept cleanup across all groups with one bounded final family check;
retain unresolved owners and successful-peer completion across retries.

Validation: npm run check, docs:check and test discovery passed. Focused
ownership/consumer coverage totals 513 passed and 1 skipped across 35 files,
including the corrected Electron cancellation test rerun independently. Darwin helper compilation, real
owned Node child cleanup, CLI/MCP capture and retained cleanup retries ran.
Real Electron applications, native Linux races/PID reuse and Windows cleanup
were not qualified. The original Linux reports remain open for that work.

Fixes #5238
Refs #4322, #5206

bridge/process/ProcessRunTokenReader.swift

@@ -12,16 +12,29 @@ struct ProcessIdentityObservation: Encodable {
   let pid: Int32
   let state: String
   let identity: String?
+  let effective_uid: UInt32?
+  let lifecycle: String?
+  let relation: ProcessRelationObservation?
   let reason: String?
 }
 
-private struct ProcessMetadata {
+struct ProcessRelationObservation: Encodable {
+  let state: String
+  let parent_pid: Int32
+  let process_group_id: Int32
+}
+
+struct ProcessMetadata {
   let identity: String
+  let effectiveUid: UInt32
+  let lifecycle: String
+  let parentPid: Int32
+  let processGroupId: Int32
   let pointerSize: Int
 }
 
 struct ProcessSnapshot {
-  fileprivate let metadata: [Int32: ProcessMetadata]
+  let metadata: [Int32: ProcessMetadata]
   let failure: String?
 }
 
@@ -75,6 +88,10 @@ func readProcessSnapshot(
           process.kp_proc.p_pid,
           ProcessMetadata(
             identity: "\(start.tv_sec):\(start.tv_usec)",
+            effectiveUid: process.kp_eproc.e_ucred.cr_uid,
+            lifecycle: process.kp_proc.p_stat == SZOMB ? "zombie" : "non-zombie",
+            parentPid: process.kp_eproc.e_ppid,
+            processGroupId: process.kp_eproc.e_pgid,
             pointerSize: process.kp_proc.p_flag & P_LP64 != 0 ? 8 : 4
           )
         )
@@ -87,20 +104,61 @@ func readProcessSnapshot(
 }
 
 func readProcessIdentities(pids: [Int32]) -> [ProcessIdentityObservation] {
-  let snapshot = readProcessSnapshot()
+  readProcessIdentities(pids: pids, snapshot: readProcessSnapshot())
+}
+
+func readProcessIdentities(
+  pids: [Int32],
+  snapshot: ProcessSnapshot
+) -> [ProcessIdentityObservation] {
   return pids.map { pid in
+    guard pid > 0 else {
+      return unavailableIdentity(pid: pid, reason: "invalid_process_id")
+    }
     guard let metadata = snapshot.metadata[pid] else {
-      return unavailableIdentity(
+      if let failure = snapshot.failure {
+        return unavailableIdentity(pid: pid, reason: failure)
+      }
+      // This records absence from this successful KERN_PROC_ALL snapshot only.
+      // Unlike the Linux procfs path, it has no PID-specific kill(0)
+      // corroboration; callers must not treat it as universal or future exit
+      // proof.
+      return ProcessIdentityObservation(
         pid: pid,
-        reason: snapshot.failure ?? "process_not_in_snapshot"
+        state: "absent",
+        identity: nil,
+        effective_uid: nil,
+        lifecycle: nil,
+        relation: nil,
+        reason: "not-in-snapshot"
       )
     }
-    return ProcessIdentityObservation(pid: pid, state: "readable", identity: metadata.identity, reason: nil)
+    return ProcessIdentityObservation(
+      pid: pid,
+      state: "readable",
+      identity: metadata.identity,
+      effective_uid: metadata.effectiveUid,
+      lifecycle: metadata.lifecycle,
+      relation: ProcessRelationObservation(
+        state: "observed",
+        parent_pid: metadata.parentPid,
+        process_group_id: metadata.processGroupId
+      ),
+      reason: nil
+    )
   }
 }
 
 private func unavailableIdentity(pid: Int32, reason: String) -> ProcessIdentityObservation {
-  ProcessIdentityObservation(pid: pid, state: "unavailable", identity: nil, reason: reason)
+  ProcessIdentityObservation(
+    pid: pid,
+    state: "unavailable",
+    identity: nil,
+    effective_uid: nil,
+    lifecycle: nil,
+    relation: nil,
+    reason: reason
+  )
 }
 
 enum RunTokenReadError: Error {