feat(hermes): add compression config form

tests/hermes-compression-config.test.js

@@ -0,0 +1,88 @@
+import test from 'node:test'
+import assert from 'node:assert/strict'
+
+import {
+  buildHermesCompressionConfigValues,
+  mergeHermesCompressionConfig,
+} from '../scripts/dev-api.js'
+
+test('Hermes 压缩配置读取会提供上游默认值', () => {
+  const values = buildHermesCompressionConfigValues({})
+
+  assert.deepEqual(values, {
+    enabled: true,
+    threshold: 0.5,
+    targetRatio: 0.2,
+    protectLastN: 20,
+    protectFirstN: 3,
+    abortOnSummaryFailure: false,
+  })
+})
+
+test('Hermes 压缩配置读取会回显 YAML 中的压缩字段', () => {
+  const values = buildHermesCompressionConfigValues({
+    compression: {
+      enabled: false,
+      threshold: 0.65,
+      target_ratio: 0.35,
+      protect_last_n: 30,
+      protect_first_n: 0,
+      abort_on_summary_failure: true,
+    },
+  })
+
+  assert.equal(values.enabled, false)
+  assert.equal(values.threshold, 0.65)
+  assert.equal(values.targetRatio, 0.35)
+  assert.equal(values.protectLastN, 30)
+  assert.equal(values.protectFirstN, 0)
+  assert.equal(values.abortOnSummaryFailure, true)
+})
+
+test('Hermes 压缩配置保存会保留无关 YAML 并写入 snake_case 字段', () => {
+  const next = mergeHermesCompressionConfig({
+    model: { provider: 'anthropic', default: 'claude-sonnet-4-6' },
+    compression: {
+      enabled: true,
+      threshold: 0.5,
+      custom_flag: 'keep-me',
+    },
+    streaming: { enabled: true },
+  }, {
+    enabled: false,
+    threshold: '0.7',
+    targetRatio: '0.4',
+    protectLastN: '28',
+    protectFirstN: '0',
+    abortOnSummaryFailure: true,
+  })
+
+  assert.deepEqual(next.model, { provider: 'anthropic', default: 'claude-sonnet-4-6' })
+  assert.deepEqual(next.streaming, { enabled: true })
+  assert.equal(next.compression.enabled, false)
+  assert.equal(next.compression.threshold, 0.7)
+  assert.equal(next.compression.target_ratio, 0.4)
+  assert.equal(next.compression.protect_last_n, 28)
+  assert.equal(next.compression.protect_first_n, 0)
+  assert.equal(next.compression.abort_on_summary_failure, true)
+  assert.equal(next.compression.custom_flag, 'keep-me')
+})
+
+test('Hermes 压缩配置保存会拒绝越界比例和消息数量', () => {
+  assert.throws(
+    () => mergeHermesCompressionConfig({}, { threshold: '0' }),
+    /compression\.threshold/,
+  )
+  assert.throws(
+    () => mergeHermesCompressionConfig({}, { targetRatio: '0.05' }),
+    /compression\.target_ratio/,
+  )
+  assert.throws(
+    () => mergeHermesCompressionConfig({}, { protectLastN: '0' }),
+    /compression\.protect_last_n/,
+  )
+  assert.throws(
+    () => mergeHermesCompressionConfig({}, { protectFirstN: '-1' }),
+    /compression\.protect_first_n/,
+  )
+})