feat: add catlog command, agent flag reorder, and TUI polish

- Add `coinhunter catlog` with limit/offset pagination for audit logs
- Optimize audit log reading with deque to avoid loading all history
- Allow `-a/--agent` flag after subcommands
- Fix upgrade spinner artifact and empty line issues
- Render audit log TUI as timeline with low-saturation event colors
- Convert audit timestamps to local timezone in TUI
- Remove futures-related capabilities
- Add conda environment.yml for development
- Bump version to 2.0.9 and update README

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/coinhunter/audit.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import json
+from collections import deque
 from datetime import datetime, timezone
 from pathlib import Path
 from typing import Any
@@ -37,3 +38,33 @@ def audit_event(event: str, payload: dict[str, Any], paths: RuntimePaths | None
     with _audit_path(paths).open("a", encoding="utf-8") as handle:
         handle.write(json.dumps(entry, ensure_ascii=False, default=json_default) + "\n")
     return entry
+
+
+def read_audit_log(paths: RuntimePaths | None = None, limit: int = 10, offset: int = 0) -> list[dict[str, Any]]:
+    paths = ensure_runtime_dirs(paths or get_runtime_paths())
+    logs_dir = _resolve_audit_dir(paths)
+    if not logs_dir.exists():
+        return []
+    audit_files = sorted(logs_dir.glob("audit_*.jsonl"), reverse=True)
+    needed = offset + limit
+    chunks: list[list[dict[str, Any]]] = []
+    total = 0
+    for audit_file in audit_files:
+        remaining = needed - total
+        if remaining <= 0:
+            break
+        entries: list[dict[str, Any]] = []
+        with audit_file.open("r", encoding="utf-8") as handle:
+            entries = list(deque((json.loads(line) for line in handle if line.strip()), maxlen=remaining))
+        if entries:
+            chunks.append(entries)
+            total += len(entries)
+    if not chunks:
+        return []
+    all_entries: list[dict[str, Any]] = []
+    for chunk in reversed(chunks):
+        all_entries.extend(chunk)
+    start = -(offset + limit) if (offset + limit) <= len(all_entries) else -len(all_entries)
+    if offset == 0:
+        return all_entries[start:]
+    return all_entries[start:-offset]