feat: add experimental pushy delivery mode

Assistant: codex
Assistant-Model: gpt-5.6-sol
Assistant-Session: 01a03397-4d51-7fd1-8ff2-946eb22ea2bc

SCOPE.md

@@ -21,6 +21,8 @@ tamq does not choose or infer them.
   display, a recipient-aware inline composer, and explicit pull-time filters.
 - Sanitized one-time output notifications through target tmux pane PTYs, with
   inbox-only delivery as an explicit option and no foreground-process input.
+- Explicit experimental pushy delivery that submits a sanitized comment and
+  Enter to target pane input for known queue-capable interactive programs.
 - Explicit opt-in control-mode pane delivery and the full-duplex `tamq tap` PTY
   broker for integration experiments.
 - Exact `gita` repository validation and direct `@repo: message` routing.
@@ -34,8 +36,9 @@ tamq does not choose or infer them.
 - Owning goal planning, workflow scheduling, or cross-host coordination; those
   belong to `coordination-engine` and its consumers.
 - Acting as a network-accessible or multi-host message broker.
-- Selecting a coding agent, starting one implicitly, or assuming a pane accepts
-  machine-generated terminal input.
+- Selecting a coding agent, starting one implicitly, or silently assuming a
+  pane accepts machine-generated input; pushy delivery requires explicit mode
+  selection by the operator.
 - Bypassing `gita` registration or injecting arbitrary pane input outside the
   supported tap/control-mode boundaries.
 - Owning tmux, Codex, State Hub, or adjacent repositories' lifecycle.
@@ -53,6 +56,7 @@ transport.
 | Local socket service | Implemented | Peer-credential checks and structured ping/register/send/history/ack/endpoints/disconnect operations are tested. |
 | Neutral tmux session lifecycle | Implemented for local alpha | Repository-first startup opens untouched shells at exact gita paths, exports per-window identity, and runs no initial command unless `--command` is explicit. Stable reuse, service restart, and cleanup are covered by the installed-package test. |
 | Safe manual messaging | Implemented for local alpha | Normal endpoints write one sanitized comment above a stable shell input row without injecting stdin; conservative fallback handles the first row and alternate screens. Messages remain pending until acknowledgement. Inbox-only manual mode is explicit with `--no-display`. |
+| Experimental pushy delivery | Explicit opt-in | `--mode pushy` submits one sanitized sender-labelled comment plus Enter through a checked tmux command. It marks successful delivery `injected`, but cannot identify pane occupants or protect input already being edited. |
 | Full-duplex input observation | Explicit opt-in | `--tap --command ...` enables the PTY integration path. It is absent from neutral startup and remains covered for geometry, resize, raw mouse input, and lifecycle behavior. |
 | Bounded retry behavior | Not enforced | Failed output or injection remains pending and becomes claimable after lease expiry, but no attempt counter or terminal failure state applies the configured cap. |
 | Acknowledgement policy | Partially implemented | Terminal output remains pending until explicit acknowledgement, while legacy pane injection becomes `injected`; the configured `delivery_ack_mode` does not yet govern both paths. |
@@ -76,6 +80,8 @@ Suitable today:
   gita-registered repositories.
 - Durable manual message exchange between managed repository windows, including
   explicit pull-time loggers and filters.
+- Controlled experiments with pushy delivery to coding-agent interfaces known
+  to queue asynchronous user prompts.
 - Developing and testing the future coordination-engine adapter against the
   local socket boundary.
 
@@ -83,11 +89,13 @@ Not yet suitable:
 
 - Unattended pane injection where bounded retries and positive recipient
   acknowledgement are required.
+- Pushy delivery to arbitrary shells, editors, or panes with unknown input
+  state.
 - Production-style operation without longer-running crash/terminal soak tests
   and stronger process-supervision evidence.
 - Cross-host messaging or use as a general-purpose broker.
 
-The suite currently has 109 passing tests and 76% statement coverage. Coverage
+The suite currently has 117 passing tests and 77% statement coverage. Coverage
 is strongest in durable storage and registry handling, and weakest in the PTY
 tap and CLI orchestration; PTY statement coverage increased from 23% to 33%,
 while subprocess behavior is primarily proven by the real-tmux test. The