fix(adapters): read tool_input.* in signal-detect for Claude Code

[TanveerKahlon]

Summary

The Claude Code adapter's signal-detect hook (`src/adapters/scripts/evolver-signal-detect.js`) silently returns `{}` on every real `PostToolUse` event because it reads `content`/`file_path` from the top level of the JSON payload, but Claude Code nests tool args under `tool_input` (`tool_input.content`, `tool_input.file_path`).

Net effect on a default install: the `[Evolution Signal] Detected: [...]` context block never fires. Session-start and session-end hooks are unaffected; only signal-detect is silently dead.

The fix

Check `tool_input.*` and `tool_response.filePath` first, fall back to the legacy top-level shape for backward compatibility. Also pick up `new_string` so Edit-tool payloads are analysed (previously only Write was reachable).

```diff

• const content = input.content || input.file_content || input.diff || '';
• const filePath = input.path || input.file_path || '';

• const ti = input.tool_input || {};
• const tr = input.tool_response || {};
• const content = ti.content || ti.new_string || ti.file_content
• || input.content || input.file_content || input.diff || '';
• const filePath = ti.file_path || tr.filePath
• || input.path || input.file_path || '';
  ```

Verification

Pipe-tested against four payload shapes:

#	Shape	Before	After
1	Claude Code `Write` (`tool_input.content`)	`{}`	signals detected
2	Claude Code `Edit` (`tool_input.new_string`)	`{}`	signals detected
3	Legacy top-level (`content`)	signals detected	signals detected (preserved)
4	Empty / no signal keywords	`{}`	`{}`

Reference for the Claude Code payload shape: https://docs.claude.com/en/docs/claude-code/hooks-guide#hook-input

Scope

• Single file changed: `src/adapters/scripts/evolver-signal-detect.js` (+8/-2)
• No behavior change for non-Claude-Code adapters or legacy callers
• No docs needed; this restores intended documented behavior