fix(opencode): fix memory-inject race condition, empty-memory ban, add turn limit

Three critical fixes to the iai-mcp-memory-inject.js plugin:

- Race condition: inflight is now a Map<sessionID, Promise> so concurrent
  callers (warm-on-create event + first transform hook) await the same
  fetch instead of getting empty string. First turn now gets memory.
- Empty-memory ban: fetchMemory returns {ok, text} tuple. HTTP 200 with
  empty body is memoized as valid (new user, minimal mode). Only actual
  network errors count against the retry budget.
- Turn-limited injection: new INJECT_MAX_TURNS (default 3) stops injecting
  after N turns. Memory was already in system prompt; the model has seen
  it. Controls per-turn token cost that was 50x the old approach.

Also: README now documents memory-inject.js (not session-init), and
session-init.js is marked @deprecated.

deploy/opencode/iai-mcp-memory-inject.js

@@ -26,11 +26,13 @@ const HOME = process.env.HOME || process.cwd();
 const PORT_FILE = `${HOME}/.iai-mcp/.http.port`;
 const WAKE_DEPTH = process.env.IAI_MCP_WAKE_DEPTH || "standard";
 const FETCH_TIMEOUT_MS = 10000; // a cold runtime-graph build can exceed 5s
-const MAX_ATTEMPTS = 3; // give up after this many failed fetches per session
+const MAX_ATTEMPTS = 3; // give up after this many consecutive failed fetches per session
+const INJECT_MAX_TURNS = 3; // stop injecting after N turns (token-cost control)
 
-const memo = new Map(); // sessionID -> injected text (cached on success)
-const attempts = new Map(); // sessionID -> failed-fetch count
-const inflight = new Set(); // sessionIDs with a fetch in flight (dedupe warm+inject)
+const memo = new Map(); // sessionID -> injected text | null (null = permanent failure)
+const inflight = new Map(); // sessionID -> Promise (await for concurrent callers)
+const attempts = new Map(); // sessionID -> consecutive-failed-fetch count
+const turns = new Map(); // sessionID -> number of times memory was injected
 
 async function readPort() {
   const fs = await import("node:fs");
@@ -44,17 +46,19 @@ async function readPort() {
 
 async function fetchMemory(sessionId) {
   const port = await readPort();
-  if (!port) return "";
+  if (!port) return { ok: false, text: "" };
   const url =
     `http://127.0.0.1:${port}/memory/session-context` +
     `?session_id=${encodeURIComponent(sessionId)}` +
     `&wake_depth=${encodeURIComponent(WAKE_DEPTH)}&format=text`;
   try {
     const res = await fetch(url, { signal: AbortSignal.timeout(FETCH_TIMEOUT_MS) });
-    if (!res.ok) return "";
-    return (await res.text()).trim();
+    const text = (await res.text()).trim();
+    // Distinguish network failure from valid-but-empty response.
+    // An empty body on HTTP 200 is a valid result (new user, minimal mode).
+    return { ok: res.ok, text };
   } catch {
-    return "";
+    return { ok: false, text: "" };
   }
 }
 
@@ -62,17 +66,41 @@ async function fetchMemory(sessionId) {
 // transform hook share ONE in-flight fetch, one cache, and one attempt budget.
 // This dedupes concurrent calls so a session never emits duplicate daemon-side
 // session_started events.
+//
+// Fix: inflight stores a Promise so concurrent callers await the same fetch
+// instead of getting "". Fix: memo stores null for permanent failure so we
+// don't retry forever. Fix: distinguish {ok:true,text:""} (valid empty) from
+// {ok:false} (network error).
 async function ensureMemory(sessionId) {
+  // Already resolved — return cached value (may be "" or null).
   const cached = memo.get(sessionId);
   if (cached !== undefined) return cached;
-  if (inflight.has(sessionId)) return ""; // a fetch is already running
-  if ((attempts.get(sessionId) || 0) >= MAX_ATTEMPTS) return "";
-  inflight.add(sessionId);
-  try {
-    const text = await fetchMemory(sessionId);
-    if (text) memo.set(sessionId, text);
-    else attempts.set(sessionId, (attempts.get(sessionId) || 0) + 1);
+
+  // A fetch is already running — await it instead of returning "".
+  const existing = inflight.get(sessionId);
+  if (existing) return existing;
+
+  // Permanent failure — stop retrying.
+  if ((attempts.get(sessionId) || 0) >= MAX_ATTEMPTS) {
+    memo.set(sessionId, null);
+    return null;
+  }
+
+  const promise = (async () => {
+    const { ok, text } = await fetchMemory(sessionId);
+    if (ok) {
+      // HTTP 200 — memoize regardless of content (empty is valid).
+      memo.set(sessionId, text);
+      attempts.delete(sessionId); // reset failure counter on success
+    } else {
+      // Network error — increment counter for retry budget.
+      attempts.set(sessionId, (attempts.get(sessionId) || 0) + 1);
+    }
     return text;
+  })();
+  inflight.set(sessionId, promise);
+  try {
+    return await promise;
   } finally {
     inflight.delete(sessionId);
   }
@@ -98,8 +126,16 @@ export const IaiMcpMemoryInject = async () => {
       try {
         const sid = input?.sessionID;
         if (!sid || !output || !Array.isArray(output.system)) return;
+
+        // Turn-limited injection: stop after INJECT_MAX_TURNS to control token cost.
+        // Memory was already in the system prompt for the first N turns; the model
+        // has seen it and doesn't need repetition every turn.
+        const currentTurns = turns.get(sid) || 0;
+        if (currentTurns >= INJECT_MAX_TURNS) return;
+
         const text = await ensureMemory(sid);
         if (text) {
+          turns.set(sid, currentTurns + 1);
           output.system.push(`# iai-mcp memory (session start)\n${text}`);
         }
       } catch (err) {

deploy/opencode/iai-mcp-session-init.js

@@ -1,8 +1,17 @@
 /**
- * iai-mcp session-init plugin for OpenCode.
+ * @deprecated Use `iai-mcp-memory-inject.js` instead.
  *
- * Sends SDK prompt on session.updated to inject the system instruction.
- * The model calls memory_session_context on every new session.
+ * This plugin forces a tool call via a phantom "INIT" user turn, which
+ * corrupts session title generation. The memory-inject plugin uses the
+ * system.transform hook to inject memory directly into the system prompt
+ * — no phantom turn, clean titles, memory visible every turn.
+ *
+ * Retained temporarily for backward compatibility. Will be removed in a
+ * future release. Migrate to iai-mcp-memory-inject.js:
+ *
+ *   cp deploy/opencode/iai-mcp-memory-inject.js ~/.config/opencode/plugins/
+ *
+ * Then replace this plugin reference in ~/.config/opencode/config.json.
  */
 
 export const IaiMcpSessionInit = async ({