diff --git a/docs/explore-notes/conpty-sessions.md b/docs/explore-notes/conpty-sessions.md
index 6d477b1f..8984a383 100644
--- a/docs/explore-notes/conpty-sessions.md
+++ b/docs/explore-notes/conpty-sessions.md
@@ -1,8 +1,8 @@
 # ConPTY interactive sessions & launch specs
 
 > **Explore-note — verify before trusting.** Distilled map of a subsystem, not authoritative.
-> Last verified against commit `f6cb825` (2026-08-05).
-> Drift check: `git log --oneline f6cb825..HEAD -- src/ClaudeDo.Worker/Planning src/ClaudeDo.Worker/Hub src/ClaudeDo.Ui/ViewModels/MissionControlViewModel.cs src/ClaudeDo.Ui/Views/InteractiveTerminalView.axaml`
+> Last verified against commit `bdee731` (2026-08-05).
+> Drift check: `git log --oneline bdee731..HEAD -- src/ClaudeDo.Worker/Planning src/ClaudeDo.Worker/Hub src/ClaudeDo.Worker/Runner/ClaudeArgsBuilder.cs src/ClaudeDo.Ui/ViewModels/MissionControlViewModel.cs src/ClaudeDo.Ui/Views/InteractiveTerminalView.axaml`
 > Stable structure only (no line numbers). See docs/explore-notes/README.md.
 
 Covers `InteractiveLaunchSpecService` and the four kinds of embedded ConPTY session the UI
@@ -108,6 +108,47 @@ reaches the PTY**. See the note in `src/ClaudeDo.Ui/CLAUDE.md`.
 tapping it jumps to that Mission Control pane. `TasksIslandViewModel.SyncInteractiveSessions`
 mirrors Mission Control's open panes onto the rows.
 
+## System-prompt matrix (autonomous vs. interactive)
+
+Autonomous and interactive sessions do **not** share a system prompt. Per start path:
+
+| Start path | Entry point | System prompt |
+|---|---|---|
+| Autonomous run/continue/retry | `TaskRunner.ResolveConfigAsync` → `ClaudeArgsBuilder.Build` | `--append-system-prompt <text>`, recomputed and re-sent on **every** invocation including a `--resume` continue (`PromptKind.System` + improvement/list/task overrides) |
+| Interactive task session, fresh | `InteractiveLaunchSpecService.BuildForTaskAsync` → `BuildFreshTaskArgsAsync` | none — no `--append-system-prompt(-file)` at all |
+| Interactive task session, resume | `InteractiveLaunchSpecService.BuildForTaskAsync` → `WindowsTerminalLauncher.BuildResumeArgs` | none — only `--resume <id>` (+ `--effort`) |
+| Ad-hoc directory session | `InteractiveLaunchSpecService.BuildForDirectoryAsync` | none |
+| Planning session start | `InteractiveLaunchSpecService.BuildPlanningStart` → `WindowsTerminalLauncher.BuildPlanningStartArgs` | `--append-system-prompt-file <path>` (`PromptKind.Planning`) |
+| Planning session resume | `InteractiveLaunchSpecService.BuildPlanningResume` → `WindowsTerminalLauncher.BuildPlanningResumeArgs` | none — only `--permission-mode default --allowedTools <planning allowlist> --resume <id>` |
+| List handler ("Let Claude handle it") | `InteractiveLaunchSpecService.BuildForMergeHelperAsync` | `--append-system-prompt-file <path>` (`PromptKind.MergeHelper`), always fresh — this path never resumes |
+
+So every interactive resume (task session and planning) drops the system prompt entirely — it's
+not that they inherit the autonomous one, it's that **no** `claude` process on any resume path
+ever passes `--append-system-prompt(-file)`.
+
+### Does `--resume` bring back a prior `--append-system-prompt`? No.
+
+Checked by reading real session transcripts (`~/.claude/projects/<cwd>/<sessionId>.jsonl`) for
+several autonomous ClaudeDo task runs, including ones with multiple invocations (initial run +
+`ContinueAsync`/retry on the same session id, confirmed via that project's `task_runs` history).
+Grepped for the `PromptKind.System` default text ("You are completing one well-defined task
+autonomously...") and for any `"type":"system"` entry or `message.role == "system"` anywhere in
+those files: the prompt text only ever showed up as ordinary tool-result content (e.g. a task
+that happened to read `PromptFiles.cs`'s own source), never as a persisted system/config entry.
+No session transcript — autonomous or interactive — carries a system-role message or a
+per-session record of the CLI flags it was launched with; there is no sidecar file next to the
+`.jsonl` either. The system prompt is purely a per-process request parameter the CLI builds fresh
+from that invocation's own flags, never replayed from a resumed session's history. This matches
+why `TaskRunner.ContinueAsync` (autonomous) explicitly re-resolves and re-passes
+`--append-system-prompt` on every continue instead of relying on `--resume` to carry it —
+if inheritance worked, that re-resolution would be redundant.
+
+**Conclusion: no leak.** An interactive resume (task or planning) does not pick up the autonomous
+run's `--append-system-prompt` text — including the "commit your work" / `CLAUDEDO_BLOCKED`
+instructions from `PromptKind.System`. It simply runs with the `claude` CLI's own baseline system
+prompt, same as every other path in this table that passes no system-prompt flag. No code change
+needed here.
+
 ## Related hub methods
 
 `GetInteractiveLaunchSpec`, `GetAdHocLaunchSpec`, `GetMergeHelperLaunchSpec`,