feat: add native Node.js RTK output filtering (FAR-66)

Replace the init-container RTK binary approach with a self-contained
Node.js implementation. When `enableRtk: true` is set in adapter config,
the job's main container startup:

1. Writes a Node.js filter script to /tmp/.rtk-filter.js (base64-encoded
   inline — no curl, no wget, no external binary download required).
2. Merges a PostToolUse hook into ~/.claude/settings.json so Claude Code
   runs the filter after every tool call.
3. The filter truncates tool_response/tool_result content that exceeds
   `rtkMaxOutputBytes` (default: 50 000 B), handling both string and
   array (text-block) content formats.

New config fields:
  enableRtk            toggle  — off by default
  rtkMaxOutputBytes    number  — truncation threshold (default 50 000)

9 new tests cover: command shape, ordering, no-external-binary guarantee,
threshold injection, PostToolUse hook presence, and filter-script logic.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

src/server/config-schema.ts

@@ -133,6 +133,21 @@ export function getConfigSchema(): AdapterConfigSchema {
       label: "Labels",
       hint: "Extra labels added to Job metadata. One key=value per line.",
     },
+    // Output filtering (RTK-compatible)
+    {
+      type: "toggle",
+      key: "enableRtk",
+      label: "Enable Output Filtering",
+      hint: "Truncate oversized tool outputs before they reach the model, reducing token consumption. Implemented natively in Node.js — no external binary required. Installs a PostToolUse hook in ~/.claude/settings.json for each run.",
+      default: false,
+    },
+    {
+      type: "number",
+      key: "rtkMaxOutputBytes",
+      label: "Max Tool Output Bytes",
+      hint: "Maximum bytes of tool output to pass to the model when output filtering is enabled. Outputs exceeding this threshold are truncated with a summary. Default: 50000.",
+      default: 50000,
+    },
   ];
 
   return { fields };