fix(engine): honor require_approval — the pause contract, implemented (PAUSE-CONTRACT + BUG-LEAK source fixes)

Two consent-flow fixes, gates only get stricter:

1. PAUSE-CONTRACT: the client has sent require_approval:true on every
   agentic request since Phase 1c, but needs_bridge never consulted it —
   builtin sub-escalate tools ran server-side unasked, making the app's
   Ask autonomy silently inert for that whole class. Now the flag is
   persisted per session (set/reset every request, so /approve resumes
   keep it) and ask_all bridges EVERY tool turn. Absent/false = behavior
   byte-identical to before. E2E: the exact probe that executed a write
   unasked now returns the tool_pending envelope with nothing on disk;
   full in-app circle verified (card → crash → resurrection → late
   approve → fence re-fires on re-entry).

2. BUG-LEAK: agent_workspace_root lived in ONE shared state key — any
   request that omitted a root inherited the previous session's folder
   (proven: a rootless curl session wrote into another session's run
   folder). Root is now stored per session and every request re-asserts
   its own (possibly empty) root into the shared key the guards read;
   same re-assert on the /approve and resume paths. Env fallback intact.
   LIMITATION: assumes serialized handling; true per-call scoping means
   threading session_id through dispatch — flagged for review.

Runnable C-patch for the test brain: neuron-container-build/
soul-pause-contract-20260716.patch (pause-contract only; the leak fix
needs the #23 root-write which the running C predates — source carries
both for the regen).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

chat.el

@@ -1935,8 +1935,24 @@ fn handle_chat_agentic(body: String) -> String {
     // no root (or cleared the field), and we must not overwrite a server-configured root
     // from NEURON_AGENT_ROOT with an empty string, which would silently un-scope the agent.
     let ws_root: String = json_get(body, "agent_workspace_root")
+    // BUG-LEAK fix (2026-07-16): the root used to live ONLY in the shared key, so any
+    // request that omitted it INHERITED the previous session's folder (proven: a rootless
+    // curl session wrote into another session's run folder). Now each session keeps its
+    // own copy, and every request RE-ASSERTS its own root (possibly empty) into the shared
+    // key the tool guards read — no session can ever act under another session's root.
+    // Empty state still falls through to env NEURON_AGENT_ROOT inside
+    // agent_workspace_root(), so a server-configured root survives unchanged.
+    // LIMITATION (for review): assumes serialized request handling; true per-call scoping
+    // means threading session_id through dispatch_tool/classify — deeper change, Will's call.
+    let sess_for_root: String = json_get(body, "session_id")
     if !str_eq(ws_root, "") {
+        if !str_eq(sess_for_root, "") {
+            state_set("agent_workspace_root_" + sess_for_root, ws_root)
+        }
         state_set("agent_workspace_root", ws_root)
+    } else {
+        let own_root: String = if str_eq(sess_for_root, "") { "" } else { state_get("agent_workspace_root_" + sess_for_root) }
+        state_set("agent_workspace_root", own_root)
     }
 
     // L1 safety screen — agentic path must pass the same gate as layered_cycle.
@@ -2066,6 +2082,14 @@ fn handle_chat_agentic(body: String) -> String {
 
     // Use caller-supplied session_id if provided, otherwise generate a bridge id.
     let session_id: String = if str_eq(req_session, "") { next_bridge_id() } else { req_session }
+    // PAUSE-CONTRACT fix (2026-07-16): honor the client's require_approval field — the
+    // Phase 1c contract ("the soul pauses on EVERY tool; the client's tier gate decides
+    // what actually prompts") was never implemented engine-side, which made the client's
+    // Ask autonomy silently inert for builtin sub-escalate tools. Persisted per session
+    // (set/reset on every request) so the /approve resume path keeps the same behavior
+    // for the rest of the run. Absent/false = behavior identical to before this fix.
+    let req_ask_all: String = json_get(body, "require_approval")
+    state_set("require_approval_" + session_id, if str_eq(req_ask_all, "true") { "true" } else { "" })
     // Provider fork: OpenAI-compatible providers (Ollama/OpenAI/Grok/Gemini) take the plain-completion
     // path (v1, no tools); everything else stays on the Anthropic agentic loop (the default).
     let use_openai: Bool = !str_eq(llm_base_url(), "") && str_eq(llm_wire_format(), "openai")
@@ -2126,6 +2150,12 @@ fn handle_chat_agentic(body: String) -> String {
 fn agentic_loop(session_id: String, model: String, safe_sys: String, tools_json: String, messages_in: String, h: Map, tools_log_in: String) -> String {
     let api_url: String = "https://api.anthropic.com/v1/messages"
 
+    // PAUSE-CONTRACT fix (2026-07-16): when the client asked to approve every action
+    // (require_approval on the request, persisted per session), EVERY tool turn bridges —
+    // the client's tier gate decides what actually prompts vs auto-continues. Read from
+    // session state so the /approve resume re-entry keeps the same behavior mid-run.
+    let ask_all: Bool = !str_eq(session_id, "") && str_eq(state_get("require_approval_" + session_id), "true")
+
     let messages: String = messages_in
     let final_text: String = ""
     let tools_log: String = tools_log_in
@@ -2212,7 +2242,10 @@ fn agentic_loop(session_id: String, model: String, safe_sys: String, tools_json:
         // confirm). Escalated calls suspend to the client's consent flow; the
         // /approve round-trip is the only path that executes them.
         let risk_tier: String = if is_tool_turn { classify_tool_risk(tool_name, tool_input) } else { "" }
-        let needs_bridge: Bool = is_tool_turn && (str_eq(risk_tier, "escalate") || (!is_builtin_tool(tool_name) && !is_always_allowed))
+        // PAUSE-CONTRACT fix (2026-07-16): ask_all bridges EVERYTHING — stricter only.
+        // Escalate keeps its unconditional bridge; "always allow" shortcuts never apply
+        // under ask_all (the client owns its own standing grants at its tier gate).
+        let needs_bridge: Bool = is_tool_turn && (ask_all || str_eq(risk_tier, "escalate") || (!is_builtin_tool(tool_name) && !is_always_allowed))
 
         // Built-in tools dispatch locally; bridged tools yield "" (never sent upstream).
         let tool_result_raw: String = if is_tool_turn && !needs_bridge { dispatch_tool(tool_name, tool_input) } else { "" }
@@ -2352,6 +2385,10 @@ fn agentic_resume(session_id: String, tool_use_id: String, content: String) -> S
     if str_eq(blob, "") {
         return "{\"error\":\"unknown session_id\",\"reply\":\"\"}"
     }
+    // BUG-LEAK fix (2026-07-16): re-assert THIS session's own workspace root before the
+    // loop continues — a resume must never run under whatever root the last unrelated
+    // request happened to leave in the shared key.
+    state_set("agent_workspace_root", state_get("agent_workspace_root_" + session_id))
 
     let model: String = json_get(blob, "model")
     let safe_sys: String = json_get(blob, "safe_sys")

sessions.el

@@ -677,6 +677,11 @@ fn handle_session_approve(session_id: String, body: String) -> String {
     // path for all sessions created through handle_chat_agentic / agentic_loop.
     let bridge_blob: String = state_get("mcp_bridge:" + session_id)
     if !str_eq(bridge_blob, "") {
+        // BUG-LEAK fix (2026-07-16): the approved tool executes below via dispatch_tool,
+        // whose path/command guards read the shared workspace-root key. Re-assert THIS
+        // session's own root first — an approval must never execute under whatever root
+        // the last unrelated request left behind.
+        state_set("agent_workspace_root", state_get("agent_workspace_root_" + session_id))
         // For "always": record tool_name in the always-allow list before resuming.
         // The tool_name is not stored in the bridge blob (only tool_use_id is).
         // Accept it from the body so the client can pass it along.