fix(compaction): 摘要收缩改按路由价并补齐定价访问路径

ds-review-bot 首轮意见修复：

- 摘要收缩比较改用所选节点的路由价 shadowedRouteTokenCount，修复图片消息启发式价低于带框摘要时压缩被误拒；日志影子价仍为启发式
- DeepSeek 定价经序列化器同一套 access 解析构建句柄与占位文本，消除逐图数十 token 的低估；uncatalogued 分支 JSDoc 指明复现 projectImagesForTextModel 替换
- llm-replay 在加载时拒绝纯文本模型上的 imageRequestTokens 声明
- contextBreakdown 的 README 与 JSDoc 改为等于 heuristicTokens 之和，不再声称等于路由价 surfaceTokens

packages/compaction/compaction-basic/src/region.ts

@@ -43,6 +43,8 @@ interface PreparedCompaction extends SurfaceSelection {
   readonly measurement: TokenMeasurement
   readonly selectedNodes: TokenMeasurement['nodes']
   readonly shadowedTokenCount: number
+  /** Route-priced total of the selected span; the shrink comparison's unit. */
+  readonly shadowedRouteTokenCount: number
   readonly input: SummarizationInput
 }
 
@@ -353,8 +355,10 @@ function prepareCompaction(
     selectedNodes,
     // The shadow-price protocol prices replacements with the fixed heuristic
     // so the O(1) projection fold stays in agreement with its own appends;
-    // retention and range selection read the route-priced `tokens` instead.
+    // retention, range selection, and the shrink comparison read the
+    // route-priced `tokens` instead.
     shadowedTokenCount: selectedNodes.reduce((total, node) => total + node.heuristicTokens, 0),
+    shadowedRouteTokenCount: selectedNodes.reduce((total, node) => total + node.tokens, 0),
     input: buildSummarizationInput(session, selection.shadowedSeqs),
   }
 }
@@ -373,10 +377,13 @@ async function summarizeCompaction(
     content: frameSummary(summaryResult.summary),
     source: compactCheckpointSource(compactionId, sourceCommandId),
   })
+  // The checkpoint is text-only, so its fixed-heuristic price IS its route
+  // price; comparing it against the span's route price asks the real
+  // question — does the replacement lower the next request's pressure.
   const framedSummaryTokenCount = dependencies.meter.estimateMessage(checkpointMessage)
-  if (framedSummaryTokenCount >= prepared.shadowedTokenCount) {
+  if (framedSummaryTokenCount >= prepared.shadowedRouteTokenCount) {
     throw new Error(
-      `summary is not smaller than the shadowed content (${framedSummaryTokenCount} estimated framed tokens >= ${prepared.shadowedTokenCount})`,
+      `summary is not smaller than the shadowed content (${framedSummaryTokenCount} estimated framed tokens >= ${prepared.shadowedRouteTokenCount})`,
     )
   }
   return {