diff --git a/.github/workflows/pr.yml b/.github/workflows/pr.yml
index 795beca131e1..e6490fa3943f 100644
--- a/.github/workflows/pr.yml
+++ b/.github/workflows/pr.yml
@@ -818,19 +818,16 @@ jobs:
 
       # A path filter that matches nothing exits 1 ("No test files found"), so this
       # lane cannot report success while running zero tests.
+      #
+      # The whole directory, not a curated file list. The unit shards exclude this directory
+      # wholesale, so this is the only lane that runs it, and a curated list made "in the
+      # directory" and "runs somewhere" two different facts: suites kept drifting into the gap
+      # and executing on no machine. The directory is the same boundary the shard exclusion
+      # uses, so a file cannot land between them.
       - name: Old/new client and server compatibility journeys
         run: >-
           pnpm exec vitest run --config config/vitest.config.ts
-          tests/e2e/cross-version-wire/release-checkout.unit.test.ts
-          tests/e2e/cross-version-wire/cross-version-browser-placement.unit.test.ts
-          tests/e2e/cross-version-wire/cross-version-terminal-wire.unit.test.ts
-          tests/e2e/cross-version-wire/reported-lossy-initial-snapshot.unit.test.ts
-          tests/e2e/cross-version-wire/cross-version-agent-session-wire.unit.test.ts
-          tests/e2e/cross-version-wire/cross-version-worktree-identity-downgrade.unit.test.ts
-          tests/e2e/cross-version-wire/cross-version-session-tabs-retirement-proof.unit.test.ts
-          tests/e2e/cross-version-wire/agent-session-resume-marker-downgrade.unit.test.ts
-          tests/e2e/cross-version-wire/agent-session-unproven-release-downgrade.unit.test.ts
-          tests/e2e/cross-version-wire/cross-version-worktree-ps-verdict.unit.test.ts
+          tests/e2e/cross-version-wire/
 
   managed_hook_node18:
     name: managed hooks on Node 18
diff --git a/config/scripts/cross-version-wire-lane-registration.test.mjs b/config/scripts/cross-version-wire-lane-registration.test.mjs
new file mode 100644
index 000000000000..817cf903ce54
--- /dev/null
+++ b/config/scripts/cross-version-wire-lane-registration.test.mjs
@@ -0,0 +1,183 @@
+import { existsSync, readFileSync, readdirSync } from 'node:fs'
+import { join, resolve } from 'node:path'
+import { describe, expect, it } from 'vitest'
+import { parse } from 'yaml'
+import { UNIT_EXCLUDE } from './ci-unit-files.mjs'
+import { classifyPrJobs } from './pr-code-change-scope.mjs'
+
+/**
+ * Every cross-version wire suite must run on some machine.
+ *
+ * PR CI runs `tests/e2e/**` in the sharded unit job, EXCEPT this directory: the suites here
+ * skew current code against an extracted release, which needs the full history and tags the
+ * shard's shallow clone does not have. So the shard excludes the directory wholesale and the
+ * `cross-version-wire` job is the only lane that runs it.
+ *
+ * That made the job's vitest argv the single thing deciding whether a file executes. While it
+ * was a curated list, `orchestration-delivery-downgrade`, `agent-session-death-evidence-downgrade`
+ * and `published-field-shape` landed in the directory without joining it and ran on no machine.
+ *
+ * Both halves matter and being in one is not enough: `CROSS_VERSION_WIRE_PREFIXES` in
+ * pr-code-change-scope.mjs decides whether the job RUNS for a diff, and the argv decides
+ * whether the FILE runs once the job started. So every module a suite pairs has to start the
+ * job too, or a change to it breaks the pairing on a PR that never runs the lane.
+ */
+
+const projectDir = resolve(import.meta.dirname, '../..')
+const LANE_JOB = 'cross-version-wire'
+const LANE_STEP = 'Old/new client and server compatibility journeys'
+const LANE_DIRECTORY = 'tests/e2e/cross-version-wire'
+const UNIT_TEST_WORKFLOW = '.github/workflows/unit-tests.yml'
+
+/** What `config/vitest.config.ts` collects from `tests/e2e/**`. */
+const SUITE_PATTERN = /\.unit\.test\.ts$/
+
+/**
+ * Floor for the suite population, so a broken directory read cannot make every assertion
+ * below vacuous by finding nothing. Only ever lowered when a suite is genuinely deleted.
+ */
+const SUITE_FLOOR = 9
+
+/**
+ * The release-checkout machinery extracts a tree and pairs nothing; `release-checkout.unit.test.ts`
+ * feeds it made-up paths on purpose.
+ */
+const CHECKOUT_MACHINERY = new Set([
+  'release-checkout.ts',
+  'release-checkout-tree.ts',
+  'release-checkout.unit.test.ts'
+])
+
+/** A working-tree import, static or dynamic, from a suite or a wire helper it loads through. */
+const WORKING_TREE_IMPORT = /['"]\.\.\/\.\.\/\.\.\/((?:src|mobile)\/[^'"]+)['"]/g
+
+/** A repo path handed to `importReleaseCheckoutModule`, inline or through a constant. */
+const CHECKOUT_MODULE_PATH = /['"]\/?((?:src|mobile)\/[^'"\s]+\.tsx?)['"]/g
+
+/** Floor for the paired modules found, so a scanner that stops matching cannot pass empty. */
+const PAIRED_MODULE_FLOOR = 25
+
+function readWorkflow(relativePath) {
+  return parse(readFileSync(join(projectDir, relativePath), 'utf8'))
+}
+
+/** The vitest argv of the lane's one test step. */
+function readLaneArgv() {
+  const workflow = readWorkflow('.github/workflows/pr.yml')
+  const job = workflow.jobs?.[LANE_JOB]
+  if (!job) {
+    throw new Error(
+      `No ${LANE_JOB} job in .github/workflows/pr.yml. If it was renamed, update LANE_JOB here -- do not delete this guard.`
+    )
+  }
+  const step = (job.steps ?? []).find((candidate) => candidate?.name === LANE_STEP)
+  if (!step) {
+    throw new Error(
+      `No "${LANE_STEP}" step in the ${LANE_JOB} job. If it was renamed, update LANE_STEP here -- do not delete this guard.`
+    )
+  }
+  const run = String(step.run ?? '')
+  if (!run.includes('vitest run')) {
+    throw new Error(`The "${LANE_STEP}" step no longer invokes vitest; this guard is stale.`)
+  }
+  return run.split(/\s+/).filter((token) => token.startsWith(`${LANE_DIRECTORY}`))
+}
+
+const laneArgv = readLaneArgv()
+const suites = readdirSync(join(projectDir, LANE_DIRECTORY))
+  .filter((name) => SUITE_PATTERN.test(name))
+  .map((name) => `${LANE_DIRECTORY}/${name}`)
+  .sort()
+
+function resolveModule(specifier) {
+  if (/\.tsx?$/.test(specifier)) {
+    return specifier
+  }
+  const candidates = [`${specifier}.ts`, `${specifier}.tsx`, `${specifier}/index.ts`]
+  return candidates.find((path) => existsSync(join(projectDir, path))) ?? specifier
+}
+
+/**
+ * Each module the suites load for pairing, with the first file that loads it. Only direct
+ * loads: a module reached through one (the orchestration schema, via db.ts) is gated by hand.
+ */
+function readPairedModules() {
+  const modules = new Map()
+  for (const name of readdirSync(join(projectDir, LANE_DIRECTORY)).sort()) {
+    if (!name.endsWith('.ts') || CHECKOUT_MACHINERY.has(name)) {
+      continue
+    }
+    const source = readFileSync(join(projectDir, LANE_DIRECTORY, name), 'utf8')
+    for (const pattern of [WORKING_TREE_IMPORT, CHECKOUT_MODULE_PATH]) {
+      for (const [, specifier] of source.matchAll(pattern)) {
+        const path = resolveModule(specifier)
+        if (!modules.has(path)) {
+          modules.set(path, name)
+        }
+      }
+    }
+  }
+  return modules
+}
+
+const pairedModules = readPairedModules()
+
+/** A vitest positional selects a file when it names the file or a directory above it. */
+function selectedByLane(path) {
+  return laneArgv.some((token) => path === token || path.startsWith(token))
+}
+
+describe('cross-version wire suites run somewhere', () => {
+  it('reads a plausible number of suites', () => {
+    expect(suites.length).toBeGreaterThanOrEqual(SUITE_FLOOR)
+  })
+
+  it('selects every suite in the directory from the lane argv', () => {
+    expect(laneArgv.length).toBeGreaterThan(0)
+    expect(suites.filter((path) => !selectedByLane(path))).toEqual([])
+  })
+
+  it('keeps the unit shards excluding the directory, which is what makes this lane the only one', () => {
+    const workflow = readWorkflow(UNIT_TEST_WORKFLOW)
+    const shardStep = (workflow.jobs?.test?.steps ?? []).find(
+      (step) => typeof step?.run === 'string' && step.run.includes('--shard=')
+    )
+    expect(shardStep, `no sharded vitest step in ${UNIT_TEST_WORKFLOW}`).toBeDefined()
+    // If this exclusion is ever dropped the suites gain a second lane, and the argv stops
+    // being the only thing that decides whether a file runs. Revisit this guard, do not
+    // delete it: the shallow shard clone has no tags for an extracted release to skew against.
+    // The shard applies UNIT_EXCLUDE only under this env flag; the lane's own run does not set it.
+    expect(shardStep.env?.ORCA_BALANCE_UNIT_SHARDS).toBe('1')
+    expect(UNIT_EXCLUDE).toContain(`${LANE_DIRECTORY}/**`)
+  })
+
+  it('runs the lane for a change to any suite it owns', () => {
+    for (const path of suites) {
+      expect(classifyPrJobs([path])[LANE_JOB], path).toBe(true)
+    }
+  })
+
+  it('finds a plausible number of paired modules', () => {
+    expect(
+      pairedModules.size,
+      `Only ${pairedModules.size} paired modules were recognized; the floor is ` +
+        `${PAIRED_MODULE_FLOOR}. The scanner has probably stopped matching a load shape.`
+    ).toBeGreaterThanOrEqual(PAIRED_MODULE_FLOOR)
+  })
+
+  it('pairs only modules that exist', () => {
+    const missing = [...pairedModules]
+      .filter(([path]) => !existsSync(join(projectDir, path)))
+      .map(([path, loader]) => `${path} (loaded by ${loader})`)
+    expect(missing).toEqual([])
+  })
+
+  it('runs the lane for a change to any module a suite pairs', () => {
+    const ungated = [...pairedModules]
+      .filter(([path]) => !classifyPrJobs([path])[LANE_JOB])
+      .map(([path, loader]) => `${path} (loaded by ${loader})`)
+    expect(ungated, 'add each to CROSS_VERSION_WIRE_PREFIXES in pr-code-change-scope.mjs').toEqual(
+      []
+    )
+  })
+})
diff --git a/config/scripts/pr-code-change-scope.mjs b/config/scripts/pr-code-change-scope.mjs
index 98dc914052af..f247d731159e 100644
--- a/config/scripts/pr-code-change-scope.mjs
+++ b/config/scripts/pr-code-change-scope.mjs
@@ -164,7 +164,18 @@ const CROSS_VERSION_WIRE_PREFIXES = [
   'src/main/runtime/runtime-worktree-agent-',
   'src/main/runtime/runtime-worktree-pty-agent-sources',
   'src/shared/runtime-worktree-contracts',
-  'src/renderer/src/runtime/remote-runtime-terminal-multiplexer'
+  'src/renderer/src/runtime/remote-runtime-terminal-multiplexer',
+  'src/main/runtime/rpc/methods/index.ts',
+  'src/main/runtime/runtime-subscription-registry.ts',
+  'src/shared/terminal-retirement-proof-ledger.ts',
+  'src/main/runtime/mobile-session-terminal-retirement.ts',
+  'src/main/runtime/mobile-session-terminal-retirement-proof.ts',
+  'src/main/persistence/tracking-repos/worktree-identity-migration.ts',
+  'src/main/runtime/orchestration/db.ts',
+  'src/main/runtime/orchestration/db/contract-constants.ts',
+  // Why: the orchestration downgrade suite opens a current-schema database with old code; db.ts reaches this transitively.
+  'src/main/runtime/orchestration/db/schema/',
+  'mobile/src/worktree/agent-row-display.ts'
 ]
 
 const MANAGED_HOOK_PREFIXES = [
@@ -406,6 +417,10 @@ export function classifyPrJobs(changedFiles) {
   // that is exactly the diff that changes the page this job builds. Gated on should_run it would
   // skip on every PR that can break it and run on none.
   jobs.mobile_web_app = jobs.mobile_web_app || changesMobileWebApp(changedFiles)
+  // Why outside should_run, for the same reason: the phone's `worktree ps` row reader is paired
+  // against the host, and a change to it is a mobile-only diff.
+  jobs['cross-version-wire'] =
+    jobs['cross-version-wire'] || jobDetector('cross-version-wire')(changedFiles)
   return {
     should_run: shouldRun,
     native_cache_changed: shouldRun && (emptyDiff || changedFiles.some(isNativeCacheInputPath)),
diff --git a/config/scripts/pr-code-change-scope.test.mjs b/config/scripts/pr-code-change-scope.test.mjs
index 1981623d2816..23df99865594 100644
--- a/config/scripts/pr-code-change-scope.test.mjs
+++ b/config/scripts/pr-code-change-scope.test.mjs
@@ -353,7 +353,16 @@ describe('per-job path classification', () => {
       'src/main/runtime/runtime-worktree-agent-rows.ts',
       'src/main/runtime/runtime-worktree-pty-agent-sources.ts',
       'src/shared/runtime-worktree-contracts.ts',
-      'src/renderer/src/runtime/remote-runtime-terminal-multiplexer.ts'
+      'src/renderer/src/runtime/remote-runtime-terminal-multiplexer.ts',
+      'src/main/runtime/rpc/methods/index.ts',
+      'src/main/runtime/runtime-subscription-registry.ts',
+      'src/shared/terminal-retirement-proof-ledger.ts',
+      'src/main/runtime/mobile-session-terminal-retirement.ts',
+      'src/main/runtime/mobile-session-terminal-retirement-proof.ts',
+      'src/main/persistence/tracking-repos/worktree-identity-migration.ts',
+      'src/main/runtime/orchestration/db.ts',
+      'src/main/runtime/orchestration/db/contract-constants.ts',
+      'src/main/runtime/orchestration/db/schema/migrate-v42.ts'
     ]) {
       expectClassification([file], {
         'cross-version-wire': true,
@@ -365,6 +374,9 @@ describe('per-job path classification', () => {
       ['tests/e2e/cross-version-wire/cross-version-terminal-wire.unit.test.ts'],
       { 'cross-version-wire': true }
     )
+    const phoneRowReader = classifyPrJobs(['mobile/src/worktree/agent-row-display.ts'])
+    expect(phoneRowReader.should_run).toBe(false)
+    expect(phoneRowReader['cross-version-wire']).toBe(true)
   })
 
   it('runs workflow-self-change and lockfile diffs as force-all', () => {
diff --git a/docs/reference/remote-wire-compatibility.md b/docs/reference/remote-wire-compatibility.md
index b2bcb3c40f4e..bd6eb5fcf3ae 100644
--- a/docs/reference/remote-wire-compatibility.md
+++ b/docs/reference/remote-wire-compatibility.md
@@ -192,10 +192,21 @@ Run it with:
 pnpm exec vitest run --config config/vitest.config.ts tests/e2e/cross-version-wire/cross-version-agent-session-wire.unit.test.ts
 ```
 
-The harness covers the terminal stream and the structured agent-session surface. It does
-**not** cover the session-tab sync channel, legacy agent-session publications, file or Git
-RPCs, mobile/E2EE framing, or the relay transport. A change on those paths still needs its
-own reasoning against the three rules above.
+The harness covers the terminal stream and the structured agent-session surface. The one
+agent-status path it pairs is the `worktree ps` row (`cross-version-worktree-ps-verdict.unit.test.ts`).
+It does **not** cover the session-tab sync channel, including the `agentStatus` each terminal
+tab carries to paired desktops and phones, legacy agent-session publications, file or Git RPCs,
+mobile/E2EE framing, or the relay transport. A change on those paths still needs its own
+reasoning against the three rules above.
+
+Every suite in `tests/e2e/cross-version-wire/` runs in the `cross-version-wire` PR job and
+nowhere else — the unit shards exclude the directory, because a shallow shard clone has no tags
+for an extracted release to skew against. The job therefore names the directory rather than a
+list of files. Which diffs start the job is a separate list, `CROSS_VERSION_WIRE_PREFIXES` in
+`config/scripts/pr-code-change-scope.mjs`, and every module a suite pairs must be on it.
+`config/scripts/cross-version-wire-lane-registration.test.mjs` holds both, but it sees only the
+modules a suite loads directly; one reached through them, such as the orchestration schema
+migrations behind `db.ts`, has to be added to the list by hand.
 
 ## Worked example: `agentWait` on terminal and worker reads
 
diff --git a/tests/e2e/cross-version-wire/agent-session-death-evidence-downgrade.unit.test.ts b/tests/e2e/cross-version-wire/agent-session-death-evidence-downgrade.unit.test.ts
index 96780a185176..001575587bd7 100644
--- a/tests/e2e/cross-version-wire/agent-session-death-evidence-downgrade.unit.test.ts
+++ b/tests/e2e/cross-version-wire/agent-session-death-evidence-downgrade.unit.test.ts
@@ -14,6 +14,7 @@ import { importReleaseCheckoutModule, materializeReleaseCheckout } from './relea
 const BASELINE_REF = 'v1.4.211'
 const SESSION = 'session-alpha-1'
 
+// Why the explicit budget: a cold run may extract the pinned release inside this test.
 test('an older build loads a proof of death that names its owner and its last proof of life', async () => {
   const directory = mkdtempSync(join(tmpdir(), 'orca-death-evidence-downgrade-'))
   try {
@@ -58,4 +59,4 @@ test('an older build loads a proof of death that names its owner and its last pr
   } finally {
     rmSync(directory, { recursive: true, force: true })
   }
-})
+}, 180_000)
diff --git a/tests/e2e/cross-version-wire/orchestration-delivery-downgrade.unit.test.ts b/tests/e2e/cross-version-wire/orchestration-delivery-downgrade.unit.test.ts
index 8126d33d6010..0398b4085855 100644
--- a/tests/e2e/cross-version-wire/orchestration-delivery-downgrade.unit.test.ts
+++ b/tests/e2e/cross-version-wire/orchestration-delivery-downgrade.unit.test.ts
@@ -9,6 +9,7 @@ import { importReleaseCheckoutModule, materializeReleaseCheckout } from './relea
 // Pin the last pre-v41 implementation: this contract specifically exercises status-only readers.
 const PRE_V41 = 'aac38d698ff75ac4c8658addab48ef5a83617619'
 
+// Why the explicit budget: this pins a commit no sibling shares, so a cold run extracts its own checkout.
 test('pre-v41 code opens, acknowledges and writes a current-schema database, then current code reopens it', async () => {
   const checkout = await materializeReleaseCheckout(PRE_V41)
   const baseline = await importReleaseCheckoutModule(
@@ -67,4 +68,4 @@ test('pre-v41 code opens, acknowledges and writes a current-schema database, the
     db?.close()
     rmSync(directory, { recursive: true, force: true })
   }
-})
+}, 180_000)
diff --git a/tests/e2e/cross-version-wire/release-checkout-tree.ts b/tests/e2e/cross-version-wire/release-checkout-tree.ts
index b5f97e78b242..73438b1eceaf 100644
--- a/tests/e2e/cross-version-wire/release-checkout-tree.ts
+++ b/tests/e2e/cross-version-wire/release-checkout-tree.ts
@@ -1,7 +1,9 @@
 import { readFile, readdir, rm, writeFile } from 'node:fs/promises'
 import { dirname, join, relative } from 'node:path'
 
-const CHECKOUT_PROCESS_TIMEOUT_MS = 45_000
+// Why not 45s: the lane runs the whole directory at once, so several pinned checkouts extract
+// concurrently beside running suites; this bounds a hung `git archive`, not a solo cold fill.
+const CHECKOUT_PROCESS_TIMEOUT_MS = 120_000
 const CHECKOUT_MAX_OUTPUT_BYTES = 1024 * 1024
 
 // Why: the wire endpoints only need the runtime RPC host, the renderer client, and