fix(web): read the literal, not the parsed number; project cursors and tool args

Copilot's eighth pass, three comments, all real.

- The precision check now reads the **source text**. Inferring the literal from
  `String(value)` was wrong in both directions: it accepted every full-form
  integer at or above 1e21 (`1000000000000000000001` parses to `1e21` and is
  written back as `1e+21`), and refused `2^54`, which is written out in full
  and exactly representable. `hasImpreciseIntegerLiteral` scans the draft for
  numeric tokens — skipping strings, so a digit-string value is untouched — and
  compares `BigInt(literal)` against `BigInt(Number(literal))`, which is exact.

- `""` is now reported as a surviving cursor for `tools/list` only. It builds
  its params with `cursor !== undefined` and carries the empty string
  deliberately; the other four list adapters use a truthiness check and drop
  it, so the editor showed `{"cursor":""}` while `{}` went out. The asymmetry
  looks like a latent bug in those four, but this function's job is to describe
  what the dispatch does.

- `callTool` runs every string-valued argument through `convertToolParameters`,
  so `{"count":"2"}` against a numeric schema is sent as `{"count":2}`.
  `reshapedReplayParam` now takes the tool and detects that by running the same
  conversion and comparing, rather than restating its rules — the two cannot
  drift. `tools` is threaded to `ProtocolEntry` for it, optional throughout: an
  unknown tool skips the check rather than blocking a replay.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UL9retfvAXRgvi6EWk4SY4
Signed-off-by: cliffhall <cliff@futurescale.com>

clients/web/src/components/groups/MrtrConversation/MrtrConversation.tsx

@@ -1,4 +1,5 @@
 import { useState } from "react";
+import type { Tool } from "@modelcontextprotocol/client";
 import {
   Badge,
   Collapse,
@@ -28,6 +29,12 @@ export interface MrtrConversationProps {
   /** Compact per-round layout for the narrow monitoring column. */
   embedded?: boolean;
   onReplay: (id: string, overrideParams?: ReplayParamsOverride) => void;
+  /**
+   * The connected server's tools. Forwarded to each entry only so an edited
+   * `tools/call` replay can tell whether an argument would be coerced by the
+   * schema on the way out (#2151).
+   */
+  tools?: Tool[];
   onTogglePin: (id: string) => void;
 }
 
@@ -123,6 +130,7 @@ function formatRoundLabel(index: number): string {
 }
 
 export function MrtrConversation({
+  tools,
   requestState,
   rounds,
   pinnedIds,
@@ -187,6 +195,7 @@ export function MrtrConversation({
                     onReplay(round.id, overrideParams)
                   }
                   onTogglePin={() => onTogglePin(round.id)}
+                  tools={tools}
                 />
               </Stack>
             ))}