feat(ai-tools): drop OpenCode and Grok Build

- opencode.json / grok.json leave the built-in catalog; opencode-usage.js,
  its poller, transcript branch and table creation go with it (existing
  tables and session rows stay as history).
- A Grok payload reaching the Claude hook route (Grok runs the Claude hooks
  itself) is dropped instead of recorded as tool = 'grok'.
- quota.js no longer reads Grok or OpenCode Go logins.
- Redone on v2.8.22 from c6b2892 (feat/grok-usage, never merged).

server/routes/sessions.js

@@ -843,25 +843,6 @@ router.get("/:id/transcripts", async (req, res) => {
         : [];
     return res.json({ transcripts: list });
   }
-  // OpenCode: a subagent is a child session of the store, tied to the agent
-  // row its poller made.
-  if (session.tool === "opencode") {
-    const list = [
-      { id: "main", name: "Main Agent", type: "main", has_transcript: true, db_agent_id: null },
-    ];
-    for (const sub of require("../lib/opencode-usage").subagentSessions(req.params.id)) {
-      list.push({
-        id: sub.id,
-        name: sub.name,
-        type: "subagent",
-        subagent_type: "task",
-        has_transcript: true,
-        db_agent_id: stmts.getAgent.get(sub.rowId) ? sub.rowId : null,
-      });
-    }
-    return res.json({ transcripts: list });
-  }
-
   const result = [];
 
   // Query database agent list for db_agent_id association
@@ -1101,20 +1082,6 @@ router.get("/:id/transcript", async (req, res) => {
   const isCursor = session.tool === "cursor";
   // An agy conversation's step log (`transcript_full.jsonl`), found by antigravity-usage.js.
   const isAgy = session.tool === "antigravity";
-  // An OpenCode conversation lives in its SQLite store, not a JSONL file: read
-  // whole (one session's rows), then paged like the files below.
-  if (session.tool === "opencode") {
-    let all = null;
-    try {
-      all = require("../lib/opencode-usage").transcriptMessages(
-        req.params.id,
-        isSubagentFile ? agentId : null
-      );
-    } catch {
-      all = null;
-    }
-    return res.json(pageMessages(all || [], { limit, afterLine, beforeLine, offset }));
-  }
   if (isOmp) {
     jsonlPath = require("../lib/omp-usage").journalPath(req.params.id, agentId || "");
   } else if (isCursor) {
@@ -1592,42 +1559,6 @@ function agyMessage(entry, num) {
   }
 }
 
-/**
- * The transcript route's paging over a conversation already in memory (an
- * OpenCode store): message N is "line" N, so `after`/`before`/`offset` and the
- * default latest-`limit` window answer exactly as they do over a file.
- */
-function pageMessages(all, { limit, afterLine, beforeLine, offset }) {
-  const lined = all.map((m, i) => ({ ...m, line: i + 1 }));
-  let picked;
-  let hasMore;
-  if (afterLine !== null) {
-    const rest = lined.filter((m) => m.line > afterLine);
-    picked = rest.slice(0, limit);
-    hasMore = rest.length > limit;
-  } else if (beforeLine !== null) {
-    const older = lined.filter((m) => m.line < beforeLine);
-    picked = older.slice(-limit);
-    hasMore = older.length > limit;
-  } else if (offset > 0) {
-    picked = lined.slice(offset, offset + limit);
-    hasMore = lined.length > offset + limit;
-  } else {
-    picked = lined.slice(-limit);
-    hasMore = lined.length > limit;
-  }
-  const lastLine = picked.length ? picked[picked.length - 1].line : 0;
-  const firstLine = picked.length ? picked[0].line : 0;
-  for (const m of picked) delete m.line;
-  return {
-    messages: picked,
-    total: lined.length,
-    has_more: hasMore,
-    last_line: lastLine,
-    first_line: firstLine,
-  };
-}
-
 module.exports = router;
 module.exports.sessionStats = sessionStats;
 // Exported for unit tests — sender attribution is correctness-critical.