diff --git a/Cargo.lock b/Cargo.lock
index 3dee232..51f7520 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -6,7 +6,6 @@ version = 4
 name = "apsis-access"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-coverage",
  "apsis-geodesy",
  "apsis-math",
@@ -16,7 +15,6 @@ dependencies = [
 name = "apsis-antenna"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-rf",
 ]
 
@@ -24,7 +22,6 @@ dependencies = [
 name = "apsis-atmosphere"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-rf",
 ]
 
@@ -32,7 +29,6 @@ dependencies = [
 name = "apsis-conflict"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-resource",
  "apsis-schedule",
  "apsis-task",
@@ -42,9 +38,7 @@ dependencies = [
 name = "apsis-constellation"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-kepler",
- "apsis-math",
  "apsis-sgp4",
 ]
 
@@ -52,7 +46,6 @@ dependencies = [
 name = "apsis-coord"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-frames",
  "apsis-geodesy",
  "apsis-math",
@@ -66,7 +59,6 @@ version = "0.1.0"
 name = "apsis-coverage"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-geodesy",
  "apsis-math",
 ]
@@ -83,7 +75,6 @@ dependencies = [
 name = "apsis-ephemeris"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-kepler",
  "apsis-math",
 ]
@@ -91,15 +82,11 @@ dependencies = [
 [[package]]
 name = "apsis-event"
 version = "0.1.0"
-dependencies = [
- "apsis-core",
-]
 
 [[package]]
 name = "apsis-frames"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-math",
 ]
 
@@ -107,17 +94,12 @@ dependencies = [
 name = "apsis-geodesy"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-math",
 ]
 
 [[package]]
 name = "apsis-handover"
 version = "0.1.0"
-dependencies = [
- "apsis-core",
- "apsis-math",
-]
 
 [[package]]
 name = "apsis-interference"
@@ -131,7 +113,6 @@ dependencies = [
 name = "apsis-isl"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-math",
 ]
 
@@ -139,10 +120,7 @@ dependencies = [
 name = "apsis-kepler"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-math",
- "apsis-time",
- "apsis-tle",
 ]
 
 [[package]]
@@ -167,7 +145,6 @@ version = "0.1.0"
 name = "apsis-maneuver"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-kepler",
  "apsis-math",
 ]
@@ -180,8 +157,6 @@ version = "0.1.0"
 name = "apsis-mesh"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
- "apsis-math",
  "apsis-topology",
 ]
 
@@ -197,29 +172,21 @@ dependencies = [
 name = "apsis-orbit"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-ephemeris",
  "apsis-kepler",
  "apsis-maneuver",
  "apsis-math",
  "apsis-sgp4",
- "apsis-time",
  "apsis-tle",
 ]
 
 [[package]]
 name = "apsis-output"
 version = "0.1.0"
-dependencies = [
- "apsis-core",
-]
 
 [[package]]
 name = "apsis-resource"
 version = "0.1.0"
-dependencies = [
- "apsis-core",
-]
 
 [[package]]
 name = "apsis-rf"
@@ -232,8 +199,6 @@ dependencies = [
 name = "apsis-routing"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
- "apsis-math",
  "apsis-topology",
 ]
 
@@ -287,7 +252,6 @@ dependencies = [
 name = "apsis-scenario"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-resource",
  "apsis-task",
 ]
@@ -296,7 +260,6 @@ dependencies = [
 name = "apsis-schedule"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-resource",
  "apsis-task",
 ]
@@ -306,7 +269,6 @@ name = "apsis-scheduler"
 version = "0.1.0"
 dependencies = [
  "apsis-conflict",
- "apsis-core",
  "apsis-resource",
  "apsis-schedule",
  "apsis-task",
@@ -316,7 +278,6 @@ dependencies = [
 name = "apsis-sgp4"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-math",
  "apsis-time",
  "apsis-tle",
@@ -326,7 +287,6 @@ dependencies = [
 name = "apsis-sim"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-event",
  "apsis-output",
  "apsis-resource",
@@ -341,7 +301,6 @@ dependencies = [
 name = "apsis-sim-engine"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-event",
 ]
 
@@ -349,7 +308,6 @@ dependencies = [
 name = "apsis-task"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-resource",
 ]
 
@@ -357,7 +315,6 @@ dependencies = [
 name = "apsis-time"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-leap",
 ]
 
@@ -365,7 +322,6 @@ dependencies = [
 name = "apsis-tle"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-time",
 ]
 
@@ -373,7 +329,6 @@ dependencies = [
 name = "apsis-topology"
 version = "0.1.0"
 dependencies = [
- "apsis-core",
  "apsis-math",
 ]
 
diff --git a/crates/network/apsis-access/Cargo.toml b/crates/network/apsis-access/Cargo.toml
index 0d79fe0..dcc0503 100644
--- a/crates/network/apsis-access/Cargo.toml
+++ b/crates/network/apsis-access/Cargo.toml
@@ -11,7 +11,6 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-math.workspace = true
 apsis-geodesy.workspace = true
 apsis-coverage.workspace = true
diff --git a/crates/network/apsis-constellation/Cargo.toml b/crates/network/apsis-constellation/Cargo.toml
index 6c33ba2..4abcebf 100644
--- a/crates/network/apsis-constellation/Cargo.toml
+++ b/crates/network/apsis-constellation/Cargo.toml
@@ -11,7 +11,5 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
-apsis-math.workspace = true
 apsis-kepler.workspace = true
 apsis-sgp4.workspace = true
diff --git a/crates/network/apsis-coverage/Cargo.toml b/crates/network/apsis-coverage/Cargo.toml
index cd76779..88a798d 100644
--- a/crates/network/apsis-coverage/Cargo.toml
+++ b/crates/network/apsis-coverage/Cargo.toml
@@ -11,6 +11,5 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-math.workspace = true
 apsis-geodesy.workspace = true
diff --git a/crates/network/apsis-handover/Cargo.toml b/crates/network/apsis-handover/Cargo.toml
index 6cb6d23..2712599 100644
--- a/crates/network/apsis-handover/Cargo.toml
+++ b/crates/network/apsis-handover/Cargo.toml
@@ -11,5 +11,3 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
-apsis-math.workspace = true
diff --git a/crates/network/apsis-isl/Cargo.toml b/crates/network/apsis-isl/Cargo.toml
index 2e06413..a176747 100644
--- a/crates/network/apsis-isl/Cargo.toml
+++ b/crates/network/apsis-isl/Cargo.toml
@@ -11,5 +11,4 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-math.workspace = true
diff --git a/crates/network/apsis-mesh/Cargo.toml b/crates/network/apsis-mesh/Cargo.toml
index 3a616df..baefbb3 100644
--- a/crates/network/apsis-mesh/Cargo.toml
+++ b/crates/network/apsis-mesh/Cargo.toml
@@ -11,6 +11,4 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
-apsis-math.workspace = true
 apsis-topology.workspace = true
diff --git a/crates/network/apsis-routing/Cargo.toml b/crates/network/apsis-routing/Cargo.toml
index ae6c7be..3b2beaa 100644
--- a/crates/network/apsis-routing/Cargo.toml
+++ b/crates/network/apsis-routing/Cargo.toml
@@ -11,6 +11,4 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
-apsis-math.workspace = true
 apsis-topology.workspace = true
diff --git a/crates/network/apsis-topology/Cargo.toml b/crates/network/apsis-topology/Cargo.toml
index 4efb559..3d5e0fa 100644
--- a/crates/network/apsis-topology/Cargo.toml
+++ b/crates/network/apsis-topology/Cargo.toml
@@ -11,5 +11,4 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-math.workspace = true
diff --git a/crates/ops/apsis-conflict/Cargo.toml b/crates/ops/apsis-conflict/Cargo.toml
index dd02e52..127b3fc 100644
--- a/crates/ops/apsis-conflict/Cargo.toml
+++ b/crates/ops/apsis-conflict/Cargo.toml
@@ -11,7 +11,6 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-resource.workspace = true
 apsis-task.workspace = true
 apsis-schedule.workspace = true
diff --git a/crates/ops/apsis-resource/Cargo.toml b/crates/ops/apsis-resource/Cargo.toml
index 15bcac7..7add1d2 100644
--- a/crates/ops/apsis-resource/Cargo.toml
+++ b/crates/ops/apsis-resource/Cargo.toml
@@ -11,4 +11,3 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
diff --git a/crates/ops/apsis-schedule/Cargo.toml b/crates/ops/apsis-schedule/Cargo.toml
index ad7e3b2..bdc47b3 100644
--- a/crates/ops/apsis-schedule/Cargo.toml
+++ b/crates/ops/apsis-schedule/Cargo.toml
@@ -11,6 +11,5 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-resource.workspace = true
 apsis-task.workspace = true
diff --git a/crates/ops/apsis-scheduler/Cargo.toml b/crates/ops/apsis-scheduler/Cargo.toml
index dea6d72..d69a928 100644
--- a/crates/ops/apsis-scheduler/Cargo.toml
+++ b/crates/ops/apsis-scheduler/Cargo.toml
@@ -11,7 +11,6 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-resource.workspace = true
 apsis-task.workspace = true
 apsis-schedule.workspace = true
diff --git a/crates/ops/apsis-task/Cargo.toml b/crates/ops/apsis-task/Cargo.toml
index 1144c21..5ffd609 100644
--- a/crates/ops/apsis-task/Cargo.toml
+++ b/crates/ops/apsis-task/Cargo.toml
@@ -11,5 +11,4 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-resource.workspace = true
diff --git a/crates/orbit/apsis-ephemeris/Cargo.toml b/crates/orbit/apsis-ephemeris/Cargo.toml
index 595e0e2..b0a6e10 100644
--- a/crates/orbit/apsis-ephemeris/Cargo.toml
+++ b/crates/orbit/apsis-ephemeris/Cargo.toml
@@ -11,7 +11,6 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-math.workspace = true
 
 [dev-dependencies]
diff --git a/crates/orbit/apsis-kepler/Cargo.toml b/crates/orbit/apsis-kepler/Cargo.toml
index 95096a8..0879cd8 100644
--- a/crates/orbit/apsis-kepler/Cargo.toml
+++ b/crates/orbit/apsis-kepler/Cargo.toml
@@ -11,7 +11,4 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-math.workspace = true
-apsis-time.workspace = true
-apsis-tle.workspace = true
diff --git a/crates/orbit/apsis-maneuver/Cargo.toml b/crates/orbit/apsis-maneuver/Cargo.toml
index e1bd7bf..e8a881a 100644
--- a/crates/orbit/apsis-maneuver/Cargo.toml
+++ b/crates/orbit/apsis-maneuver/Cargo.toml
@@ -11,6 +11,5 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-math.workspace = true
 apsis-kepler.workspace = true
diff --git a/crates/orbit/apsis-orbit/Cargo.toml b/crates/orbit/apsis-orbit/Cargo.toml
index 8a60416..0d565df 100644
--- a/crates/orbit/apsis-orbit/Cargo.toml
+++ b/crates/orbit/apsis-orbit/Cargo.toml
@@ -11,9 +11,7 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-math.workspace = true
-apsis-time.workspace = true
 apsis-tle.workspace = true
 apsis-sgp4.workspace = true
 apsis-kepler.workspace = true
diff --git a/crates/orbit/apsis-sgp4/Cargo.toml b/crates/orbit/apsis-sgp4/Cargo.toml
index 3bcfa50..cf9c5d6 100644
--- a/crates/orbit/apsis-sgp4/Cargo.toml
+++ b/crates/orbit/apsis-sgp4/Cargo.toml
@@ -11,7 +11,6 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-math.workspace = true
 apsis-tle.workspace = true
 apsis-time.workspace = true
diff --git a/crates/orbit/apsis-tle/Cargo.toml b/crates/orbit/apsis-tle/Cargo.toml
index 5ecaf87..8745155 100644
--- a/crates/orbit/apsis-tle/Cargo.toml
+++ b/crates/orbit/apsis-tle/Cargo.toml
@@ -11,5 +11,4 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-time.workspace = true
diff --git a/crates/physics/apsis-coord/Cargo.toml b/crates/physics/apsis-coord/Cargo.toml
index 32c0476..1f72789 100644
--- a/crates/physics/apsis-coord/Cargo.toml
+++ b/crates/physics/apsis-coord/Cargo.toml
@@ -11,7 +11,6 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-math.workspace = true
 apsis-geodesy.workspace = true
 apsis-frames.workspace = true
diff --git a/crates/physics/apsis-frames/Cargo.toml b/crates/physics/apsis-frames/Cargo.toml
index 6d9c852..d104846 100644
--- a/crates/physics/apsis-frames/Cargo.toml
+++ b/crates/physics/apsis-frames/Cargo.toml
@@ -11,5 +11,4 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-math.workspace = true
diff --git a/crates/physics/apsis-geodesy/Cargo.toml b/crates/physics/apsis-geodesy/Cargo.toml
index ba0412a..affcd32 100644
--- a/crates/physics/apsis-geodesy/Cargo.toml
+++ b/crates/physics/apsis-geodesy/Cargo.toml
@@ -11,5 +11,4 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-math.workspace = true
diff --git a/crates/physics/apsis-time/Cargo.toml b/crates/physics/apsis-time/Cargo.toml
index b9affc0..d71e4f9 100644
--- a/crates/physics/apsis-time/Cargo.toml
+++ b/crates/physics/apsis-time/Cargo.toml
@@ -11,5 +11,4 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-leap.workspace = true
diff --git a/crates/rf/apsis-antenna/Cargo.toml b/crates/rf/apsis-antenna/Cargo.toml
index 8962588..48d04c3 100644
--- a/crates/rf/apsis-antenna/Cargo.toml
+++ b/crates/rf/apsis-antenna/Cargo.toml
@@ -11,5 +11,4 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-rf.workspace = true
diff --git a/crates/rf/apsis-atmosphere/Cargo.toml b/crates/rf/apsis-atmosphere/Cargo.toml
index 428fc18..3115d43 100644
--- a/crates/rf/apsis-atmosphere/Cargo.toml
+++ b/crates/rf/apsis-atmosphere/Cargo.toml
@@ -11,5 +11,4 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-rf.workspace = true
diff --git a/crates/sim/apsis-event/Cargo.toml b/crates/sim/apsis-event/Cargo.toml
index 3bc217e..b1420ab 100644
--- a/crates/sim/apsis-event/Cargo.toml
+++ b/crates/sim/apsis-event/Cargo.toml
@@ -11,4 +11,3 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
diff --git a/crates/sim/apsis-output/Cargo.toml b/crates/sim/apsis-output/Cargo.toml
index 1cf888a..053fff8 100644
--- a/crates/sim/apsis-output/Cargo.toml
+++ b/crates/sim/apsis-output/Cargo.toml
@@ -11,4 +11,3 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
diff --git a/crates/sim/apsis-scenario/Cargo.toml b/crates/sim/apsis-scenario/Cargo.toml
index 694316b..122e29f 100644
--- a/crates/sim/apsis-scenario/Cargo.toml
+++ b/crates/sim/apsis-scenario/Cargo.toml
@@ -11,6 +11,5 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-resource.workspace = true
 apsis-task.workspace = true
diff --git a/crates/sim/apsis-sim-engine/Cargo.toml b/crates/sim/apsis-sim-engine/Cargo.toml
index 4bc4b82..dd13078 100644
--- a/crates/sim/apsis-sim-engine/Cargo.toml
+++ b/crates/sim/apsis-sim-engine/Cargo.toml
@@ -11,5 +11,4 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-event.workspace = true
diff --git a/crates/sim/apsis-sim/Cargo.toml b/crates/sim/apsis-sim/Cargo.toml
index 1bd35a1..ffb6b35 100644
--- a/crates/sim/apsis-sim/Cargo.toml
+++ b/crates/sim/apsis-sim/Cargo.toml
@@ -11,7 +11,6 @@ publish = false
 workspace = true
 
 [dependencies]
-apsis-core.workspace = true
 apsis-resource.workspace = true
 apsis-task.workspace = true
 apsis-schedule.workspace = true
diff --git a/docs/design/layers.md b/docs/design/layers.md
index 71aaf6d..d10d84f 100644
--- a/docs/design/layers.md
+++ b/docs/design/layers.md
@@ -41,13 +41,19 @@ index(B) >  index(A)     违规（反向依赖）
 
 ## 全局基准
 
-`apsis-core`（错误、常量、单位标记）与 `apsis-math`（`Vec3`、`Mat3`、
-`Quat`）被各层共用，包括最左的 `foundation` 之外的所有层。它们本身在
-`foundation` 中，所以"只向左依赖"已经允许任何层使用它们，无需特例。
+`apsis-core`（通用错误、常量、单位标记）与 `apsis-math`（`Vec3`、
+`Mat3`、`Quat`）被各层共用。它们本身在 `foundation` 中，所以"只向左依赖"
+已经允许任何层使用它们，无需特例。
 
 这与"层内基准"不同：`apsis-core` 也是 `foundation` 内的基准，但它的可用
 范围是整个工作区，而不只是同层。
 
+**只有真正使用的依赖才声明。** `apsis-core` 与 `apsis-math` 可以被任何
+crate 使用，但一个不引用它们的 crate 不应把它们写进清单：未使用的依赖会
+拖慢编译、让 `cargo tree` 与分层检查产生噪声，并让"谁依赖什么"失真。
+需要时再加，是一条随时可走的单行改动。`scripts/check-layers.sh` 报告的
+边数因此是真实的使用关系，而不是一份预留清单。
+
 ## 层内门面
 
 每层以一个门面 crate 作为整合点：
@@ -80,4 +86,4 @@ bash scripts/check-layers.sh
 ```
 
 脚本输出检查过的依赖边数，并在发现反向依赖时逐条列出后以退出码 1 结束。
-对当前工作区，它检查 141 条边，全部方向正确。
+对当前工作区，它检查 104 条边，全部方向正确。