diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bc2e6e3c64..c7bd0fe430 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -280,7 +280,6 @@ jobs:
   marker-guard:
     name: Marker Guard
     runs-on: ubuntu-latest
-    if: github.event_name == 'pull_request'
     timeout-minutes: 5
     steps:
       - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
@@ -300,9 +299,20 @@ jobs:
         run: bun install
         working-directory: script/upstream
 
+      - name: Run marker parser tests
+        run: bun test
+        working-directory: script/upstream
+
       - name: Check for missing altimate_change markers
         run: |
-          if [[ "${{ github.head_ref }}" == merge-upstream-* ]] || [[ "${{ github.head_ref }}" == upstream/merge-* ]]; then
+          if [[ "${{ github.event_name }}" == "push" ]]; then
+            if [[ "${{ github.event.before }}" == "0000000000000000000000000000000000000000" ]]; then
+              echo "Initial push (zero-SHA) — skipping marker check"
+              exit 0
+            fi
+            echo "Push to main — running marker check against pre-push state"
+            bun run script/upstream/analyze.ts --markers --base "${{ github.event.before }}" --strict
+          elif [[ "${{ github.head_ref }}" == merge-upstream-* ]] || [[ "${{ github.head_ref }}" == upstream/merge-* ]]; then
             echo "Upstream merge PR detected — running marker check in non-strict mode"
             bun run script/upstream/analyze.ts --markers --base ${{ github.event.pull_request.base.ref }}
           else
diff --git a/packages/opencode/src/cli/cmd/tui/routes/home.tsx b/packages/opencode/src/cli/cmd/tui/routes/home.tsx
index 54a0e47aa2..865553899f 100644
--- a/packages/opencode/src/cli/cmd/tui/routes/home.tsx
+++ b/packages/opencode/src/cli/cmd/tui/routes/home.tsx
@@ -15,7 +15,9 @@ import { Installation } from "@/installation"
 import { useKV } from "../context/kv"
 import { useCommandDialog } from "../component/dialog-command"
 import { useLocal } from "../context/local"
+// altimate_change start — upgrade indicator import
 import { UpgradeIndicator } from "../component/upgrade-indicator"
+// altimate_change end
 
 // TODO: what is the best way to do this?
 let once = false
@@ -153,7 +155,9 @@ export function Home() {
         </box>
         <box flexGrow={1} />
         <box flexShrink={0}>
+          {/* altimate_change start — upgrade indicator in home footer */}
           <UpgradeIndicator fallback={<text fg={theme.textMuted}>{Installation.VERSION}</text>} />
+          {/* altimate_change end */}
         </box>
       </box>
     </>
diff --git a/packages/opencode/src/cli/cmd/tui/routes/session/footer.tsx b/packages/opencode/src/cli/cmd/tui/routes/session/footer.tsx
index 98cb87ebbe..c7225214c0 100644
--- a/packages/opencode/src/cli/cmd/tui/routes/session/footer.tsx
+++ b/packages/opencode/src/cli/cmd/tui/routes/session/footer.tsx
@@ -8,7 +8,9 @@ import { useRoute } from "../../context/route"
 // altimate_change start - yolo mode visual indicator
 import { Flag } from "@/flag/flag"
 // altimate_change end
+// altimate_change start — upgrade indicator import
 import { UpgradeIndicator } from "../../component/upgrade-indicator"
+// altimate_change end
 
 export function Footer() {
   const { theme } = useTheme()
@@ -96,7 +98,9 @@ export function Footer() {
             <text fg={theme.textMuted}>/status</text>
           </Match>
         </Switch>
+        {/* altimate_change start — upgrade indicator in session footer */}
         <UpgradeIndicator />
+        {/* altimate_change end */}
       </box>
     </box>
   )
diff --git a/script/upstream/analyze.test.ts b/script/upstream/analyze.test.ts
new file mode 100644
index 0000000000..ae4ae72fce
--- /dev/null
+++ b/script/upstream/analyze.test.ts
@@ -0,0 +1,290 @@
+import { describe, test, expect } from "bun:test"
+import { parseDiffForMarkerWarnings } from "./analyze"
+
+// Helper to create a unified diff string from lines
+function makeDiff(hunks: string): string {
+  return `diff --git a/file.ts b/file.ts
+index abc1234..def5678 100644
+--- a/file.ts
++++ b/file.ts
+${hunks}`
+}
+
+describe("parseDiffForMarkerWarnings", () => {
+  test("returns no warnings for empty diff", () => {
+    expect(parseDiffForMarkerWarnings("file.ts", "")).toEqual([])
+    expect(parseDiffForMarkerWarnings("file.ts", "  \n  ")).toEqual([])
+  })
+
+  test("added code inside added markers — no warning", () => {
+    const diff = makeDiff(
+      `@@ -10,3 +10,5 @@
+ const existing = true
++// altimate_change start — new feature
++const custom = true
++// altimate_change end
+ const more = true`,
+    )
+    expect(parseDiffForMarkerWarnings("file.ts", diff)).toEqual([])
+  })
+
+  test("added code without markers — warning", () => {
+    const diff = makeDiff(
+      `@@ -10,3 +10,4 @@
+ const existing = true
++const unmarked = true
+ const more = true`,
+    )
+    const warnings = parseDiffForMarkerWarnings("file.ts", diff)
+    expect(warnings).toHaveLength(1)
+    expect(warnings[0].file).toBe("file.ts")
+    expect(warnings[0].context).toContain("unmarked")
+  })
+
+  test("REGRESSION: added code inside existing (context) markers — no warning", () => {
+    // This is the exact bug that caused the upgrade indicator leak.
+    // Markers are context lines (already committed), new code is added inside.
+    const diff = makeDiff(
+      `@@ -10,4 +10,5 @@
+ const existing = true
+ // altimate_change start — existing feature
++const newCodeInsideExistingBlock = true
+ // altimate_change end
+ const more = true`,
+    )
+    expect(parseDiffForMarkerWarnings("file.ts", diff)).toEqual([])
+  })
+
+  test("REGRESSION: context marker end followed by added code — warning", () => {
+    // New code added AFTER an existing marker block should be flagged.
+    const diff = makeDiff(
+      `@@ -10,4 +10,5 @@
+ // altimate_change start — block A
+ const blockA = true
+ // altimate_change end
++const outsideBlock = true
+ const existing = true`,
+    )
+    const warnings = parseDiffForMarkerWarnings("file.ts", diff)
+    expect(warnings).toHaveLength(1)
+    expect(warnings[0].context).toContain("outsideBlock")
+  })
+
+  test("REGRESSION: context marker start, added code, context marker end — no warning", () => {
+    // Entire marker block is pre-existing (context), only the inner code is new.
+    const diff = makeDiff(
+      `@@ -8,4 +8,5 @@
+ // altimate_change start - yolo mode visual indicator
+ import { Flag } from "@/flag/flag"
+ // altimate_change end
++import { UpgradeIndicator } from "../../component/upgrade-indicator"
+ const next = true`,
+    )
+    // The import line is skipped by the "import " heuristic, so no warning
+    expect(parseDiffForMarkerWarnings("file.ts", diff)).toEqual([])
+  })
+
+  test("REGRESSION: non-import code inside existing context markers — no warning", () => {
+    // Verifies the fix works independently of the import heuristic
+    const diff = makeDiff(
+      `@@ -10,4 +10,5 @@
+ const existing = true
+ // altimate_change start — custom feature
++const customCode = doSomething()
+ // altimate_change end
+ const more = true`,
+    )
+    expect(parseDiffForMarkerWarnings("file.ts", diff)).toEqual([])
+  })
+
+  test("REGRESSION: JSX comment markers on context lines — no warning", () => {
+    // JSX uses {/* altimate_change start ... */} syntax
+    const diff = makeDiff(
+      `@@ -95,4 +95,5 @@
+ {/* altimate_change start — upgrade indicator */}
++<UpgradeIndicator />
+ {/* altimate_change end */}
+ </box>`,
+    )
+    expect(parseDiffForMarkerWarnings("file.ts", diff)).toEqual([])
+  })
+
+  test("multiple hunks — marker state resets at hunk boundary", () => {
+    // Each hunk starts fresh, marker state should NOT carry across hunks
+    // since different parts of the file may have different marker context.
+    const diff = makeDiff(
+      `@@ -5,3 +5,4 @@
+ // altimate_change start — block 1
++const inBlock = true
+ // altimate_change end
+@@ -50,3 +51,4 @@
+ const existing = true
++const unmarkedInSecondHunk = true
+ const more = true`,
+    )
+    const warnings = parseDiffForMarkerWarnings("file.ts", diff)
+    expect(warnings).toHaveLength(1)
+    expect(warnings[0].context).toContain("unmarkedInSecondHunk")
+  })
+
+  test("marker state from hunk 1 does not leak into hunk 2", () => {
+    // If hunk 1 ends inside a marker block (start without end in context),
+    // hunk 2 should NOT inherit that state.
+    const diff = makeDiff(
+      `@@ -5,3 +5,4 @@
+ // altimate_change start — block 1
++const inBlock = true
+ const moreInBlock = true
+@@ -80,3 +81,4 @@
+ const unrelated = true
++const shouldBeWarned = true
+ const end = true`,
+    )
+    const warnings = parseDiffForMarkerWarnings("file.ts", diff)
+    expect(warnings).toHaveLength(1)
+    expect(warnings[0].context).toContain("shouldBeWarned")
+  })
+
+  test("import lines are skipped even without markers", () => {
+    const diff = makeDiff(
+      `@@ -1,3 +1,4 @@
+ import { existing } from "./existing"
++import { NewThing } from "./new-thing"
+ const x = 1`,
+    )
+    expect(parseDiffForMarkerWarnings("file.ts", diff)).toEqual([])
+  })
+
+  test("export lines are skipped even without markers", () => {
+    const diff = makeDiff(
+      `@@ -1,3 +1,4 @@
+ const x = 1
++export { x }
+ const y = 2`,
+    )
+    expect(parseDiffForMarkerWarnings("file.ts", diff)).toEqual([])
+  })
+
+  test("comment-only lines are skipped (not TODOs)", () => {
+    const diff = makeDiff(
+      `@@ -1,3 +1,4 @@
+ const x = 1
++// this is a harmless comment
+ const y = 2`,
+    )
+    expect(parseDiffForMarkerWarnings("file.ts", diff)).toEqual([])
+  })
+
+  test("TODO comments are NOT skipped", () => {
+    const diff = makeDiff(
+      `@@ -1,3 +1,4 @@
+ const x = 1
++// TODO: implement custom feature
+ const y = 2`,
+    )
+    const warnings = parseDiffForMarkerWarnings("file.ts", diff)
+    expect(warnings).toHaveLength(1)
+  })
+
+  test("empty added lines are skipped", () => {
+    const diff = makeDiff(
+      `@@ -1,3 +1,4 @@
+ const x = 1
++
+ const y = 2`,
+    )
+    expect(parseDiffForMarkerWarnings("file.ts", diff)).toEqual([])
+  })
+
+  test("deleted lines don't affect marker state or line numbers", () => {
+    const diff = makeDiff(
+      `@@ -5,5 +5,5 @@
+ // altimate_change start — feature
+-const oldCode = true
++const newCode = true
+ // altimate_change end
+ const next = true`,
+    )
+    expect(parseDiffForMarkerWarnings("file.ts", diff)).toEqual([])
+  })
+
+  test("line number in warning matches diff hunk position", () => {
+    const diff = makeDiff(
+      `@@ -42,3 +42,4 @@
+ const existing = true
++const unmarked = true
+ const more = true`,
+    )
+    const warnings = parseDiffForMarkerWarnings("file.ts", diff)
+    expect(warnings).toHaveLength(1)
+    expect(warnings[0].line).toBe(43)
+  })
+
+  test("context truncated to 80 chars in warning", () => {
+    const longLine = "x".repeat(120)
+    const diff = makeDiff(
+      `@@ -1,3 +1,4 @@
+ const a = 1
++const ${longLine} = true
+ const b = 2`,
+    )
+    const warnings = parseDiffForMarkerWarnings("file.ts", diff)
+    expect(warnings).toHaveLength(1)
+    expect(warnings[0].context.length).toBeLessThanOrEqual(80)
+  })
+
+  test("only first unmarked line is reported per file", () => {
+    const diff = makeDiff(
+      `@@ -1,3 +1,5 @@
+ const a = 1
++const first = true
++const second = true
+ const b = 2`,
+    )
+    const warnings = parseDiffForMarkerWarnings("file.ts", diff)
+    expect(warnings).toHaveLength(1)
+    expect(warnings[0].context).toContain("first")
+  })
+
+  test("real-world scenario: upgrade indicator in footer.tsx", () => {
+    // Simulates the exact diff that leaked: UpgradeIndicator added to
+    // session footer without markers, adjacent to existing yolo marker block.
+    const diff = makeDiff(
+      `@@ -8,4 +8,6 @@
+ // altimate_change start - yolo mode visual indicator
+ import { Flag } from "@/flag/flag"
+ // altimate_change end
++// altimate_change start — upgrade indicator import
++import { UpgradeIndicator } from "../../component/upgrade-indicator"
++// altimate_change end
+
+@@ -96,4 +98,6 @@
+         </Switch>
++        {/* altimate_change start — upgrade indicator in session footer */}
++        <UpgradeIndicator />
++        {/* altimate_change end */}
+       </box>`,
+    )
+    expect(parseDiffForMarkerWarnings("footer.tsx", diff)).toEqual([])
+  })
+
+  test("real-world scenario: unmarked upgrade indicator would be caught", () => {
+    // Same scenario but WITHOUT markers — should flag
+    const diff = makeDiff(
+      `@@ -8,4 +8,5 @@
+ // altimate_change start - yolo mode visual indicator
+ import { Flag } from "@/flag/flag"
+ // altimate_change end
++import { UpgradeIndicator } from "../../component/upgrade-indicator"
+
+@@ -96,4 +97,5 @@
+         </Switch>
++        <UpgradeIndicator />
+       </box>`,
+    )
+    const warnings = parseDiffForMarkerWarnings("footer.tsx", diff)
+    // import is skipped by heuristic, but <UpgradeIndicator /> is flagged
+    expect(warnings).toHaveLength(1)
+    expect(warnings[0].context).toContain("UpgradeIndicator")
+  })
+})
diff --git a/script/upstream/analyze.ts b/script/upstream/analyze.ts
index f205a9989e..efbc435a38 100644
--- a/script/upstream/analyze.ts
+++ b/script/upstream/analyze.ts
@@ -606,22 +606,9 @@ function isUpstreamShared(file: string, config: MergeConfig): boolean {
   return upstreamFiles.has(file)
 }
 
-function checkFileForMarkers(file: string, base?: string): MarkerWarning[] {
-  const { execSync } = require("child_process")
-  const root = repoRoot()
+// altimate_change start — exported for unit testing
+export function parseDiffForMarkerWarnings(file: string, diffOutput: string): MarkerWarning[] {
   const warnings: MarkerWarning[] = []
-
-  const diffCmd = base
-    ? `git diff -U5 ${base}...HEAD -- "${file}"`
-    : `git diff -U5 HEAD -- "${file}"`
-
-  let diffOutput: string
-  try {
-    diffOutput = execSync(diffCmd, { cwd: root, encoding: "utf-8" })
-  } catch {
-    return warnings
-  }
-
   if (!diffOutput.trim()) return warnings
 
   const lines = diffOutput.split("\n")
@@ -635,10 +622,27 @@ function checkFileForMarkers(file: string, base?: string): MarkerWarning[] {
     const hunkMatch = line.match(/^@@ -\d+(?:,\d+)? \+(\d+)/)
     if (hunkMatch) {
       currentLine = parseInt(hunkMatch[1]) - 1
+      // Reset marker state at hunk boundaries — hunks are discontinuous
+      // regions of the file, so marker blocks from one region don't apply
+      // to another.
+      inMarkerBlock = false
       continue
     }
 
-    if (line.startsWith("+") && !line.startsWith("+++")) {
+    // altimate_change start — fix: track marker state from context lines, not just added lines
+    if (line.startsWith("-") && !line.startsWith("---")) {
+      // deleted line, don't increment
+      continue
+    }
+
+    // Both added (+) and context ( ) lines appear in the final file,
+    // so both must update marker state. Without this, existing markers
+    // on context lines are invisible and new code next to them looks
+    // unmarked — causing false positives.
+    const isAdded = line.startsWith("+") && !line.startsWith("+++")
+    const isContext = !line.startsWith("+") && !line.startsWith("-") && !line.startsWith("\\")
+
+    if (isAdded || isContext) {
       currentLine++
       const content = line.slice(1).trim()
 
@@ -646,6 +650,9 @@ function checkFileForMarkers(file: string, base?: string): MarkerWarning[] {
       if (content.includes("altimate_change end")) { inMarkerBlock = false; continue }
       if (content.includes("altimate_change")) continue
 
+      // Only flag added lines as violations — context lines are pre-existing
+      if (!isAdded) continue
+
       if (!content) continue
       if (content.startsWith("//") && !content.includes("TODO")) continue
       if (content.startsWith("import ")) continue
@@ -658,11 +665,8 @@ function checkFileForMarkers(file: string, base?: string): MarkerWarning[] {
           newCodeContext = content
         }
       }
-    } else if (line.startsWith("-")) {
-      // deleted line, don't increment
-    } else {
-      currentLine++
     }
+    // altimate_change end
   }
 
   if (hasNewCode) {
@@ -676,6 +680,25 @@ function checkFileForMarkers(file: string, base?: string): MarkerWarning[] {
 
   return warnings
 }
+// altimate_change end
+
+function checkFileForMarkers(file: string, base?: string): MarkerWarning[] {
+  const { execSync } = require("child_process")
+  const root = repoRoot()
+
+  const diffCmd = base
+    ? `git diff -U5 ${base}...HEAD -- "${file}"`
+    : `git diff -U5 HEAD -- "${file}"`
+
+  let diffOutput: string
+  try {
+    diffOutput = execSync(diffCmd, { cwd: root, encoding: "utf-8" })
+  } catch {
+    return []
+  }
+
+  return parseDiffForMarkerWarnings(file, diffOutput)
+}
 
 function runMarkerCheck(config: MergeConfig, base?: string, strict?: boolean): number {
   const { execSync } = require("child_process")
@@ -804,7 +827,11 @@ async function main(): Promise<void> {
   }
 }
 
-main().catch((e) => {
-  logger.error(`Analysis failed: ${e.message || e}`)
-  process.exit(2)
-})
+// altimate_change start — guard CLI execution when imported as a module (e.g., by tests)
+if (import.meta.main) {
+  main().catch((e) => {
+    logger.error(`Analysis failed: ${e.message || e}`)
+    process.exit(2)
+  })
+}
+// altimate_change end