feat(rust): mod configuration from the site, and an editor that will not rewrite a float

R18's two tiers: a form generated from a config file's own values, and raw JSON
for what a form cannot express. Admin → Rust mod config, one live round trip per
action, nothing cached between a browser and a game host's disk.

`configEdit.js` is the part that could not be done naively. JavaScript cannot
tell `1` from `1.0`, and both mod frameworks deserialize a config into typed C#
classes — so a read-modify-write silently rewrites every whole-numbered float as
an integer on fields nobody touched, and a plugin that then throws at load does
not come back. It never parses, mutates and re-serialises: it records the SOURCE
SPAN of every value and splices literals into them, so an untouched `1.0` is
still `1.0` and a number an admin types travels as text the whole way (D35/D36).

The bridge's own config is editable with `Host`, `Port` and `ServerId` locked,
in the form and in the raw tier, because either would cut the link carrying the
edit or strand every row this site holds (D38). Credentials render masked with a
reveal; the raw tier shows them (D37) and the audit trail never does.

`rust_config_writes` records every save including the refused and the rolled
back — an operator asking why a setting is not what they set needs to see that
somebody tried.

Three defects a browser walk found that 179 green tests did not:

* every save of the bridge's own config was refused while the page said the
  opposite — a `<select>` whose value matches no `<option>` shows the first one,
  so the reload guess `RunicGateway` was on the wire and "nothing" was on the
  screen;
* `btn ghost` is not a class this platform defines (`.btn-ghost` is), so every
  secondary button in this module has rendered as a primary one since phase 7 —
  here it made the open file and the active tier indistinguishable;
* a save's refusal rendered at the top of a long form, far from the button.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PMH6bw1jXMgbyF3ZWGEzSM

server/model/config/config.db.js

@@ -0,0 +1,79 @@
+// ── The SQL half of the configuration audit ───────────────────────────────
+//
+// One table, two questions: record what a save did, and show an operator what
+// has been done to a server lately.
+//
+// Nothing here talks to a game. The game half is `sidecarClient`, and the two
+// are deliberately not mixed: this file is what remains true after the plugin
+// has been reloaded, rolled back, or lost.
+
+const core = require('../../core')
+
+/**
+ * Records one save attempt — including the ones that never reached a file.
+ *
+ * A refusal is written for the same reason a success is: an operator asking why
+ * a setting is not what they set has to be able to see that somebody tried and
+ * was told no, and a table that only holds successes answers that question with
+ * silence.
+ */
+async function recordWrite(row) {
+  await core.query(
+    `INSERT INTO rust_config_writes
+       (server_id, path, plugin, reload_target, tier, user_id, outcome, reloaded,
+        changes, version_before, version_after, detail)
+     VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
+    [
+      row.serverId,
+      row.path,
+      row.plugin || null,
+      row.reloadTarget || null,
+      row.tier || 'form',
+      row.userId || null,
+      row.outcome,
+      row.reloaded ? 1 : 0,
+      row.changes ? JSON.stringify(row.changes) : null,
+      row.versionBefore || null,
+      row.versionAfter || null,
+      row.detail ? String(row.detail).slice(0, 500) : null,
+    ],
+  )
+}
+
+/**
+ * The recent history for one server, newest first.
+ *
+ * `changes` comes back parsed, and a row whose JSON will not parse comes back
+ * with `null` rather than throwing — a corrupt audit row must not be able to
+ * break the page that displays the rest of them.
+ */
+async function recentWrites(serverId, limit = 50) {
+  const rows = await core.query(
+    `SELECT id, server_id AS serverId, path, plugin, reload_target AS reloadTarget, tier,
+            user_id AS userId, outcome, reloaded, changes,
+            version_before AS versionBefore, version_after AS versionAfter, detail, created_at AS createdAt
+       FROM rust_config_writes
+      WHERE server_id = ?
+      ORDER BY id DESC
+      LIMIT ?`,
+    [serverId, Math.max(1, Math.min(Number(limit) || 50, 200))],
+  )
+
+  return rows.map((row) => ({
+    ...row,
+    reloaded: Boolean(row.reloaded),
+    changes: parseChanges(row.changes),
+  }))
+}
+
+function parseChanges(raw) {
+  if (!raw) return null
+
+  try {
+    return JSON.parse(raw)
+  } catch {
+    return null
+  }
+}
+
+module.exports = { recordWrite, recentWrites, parseChanges }