Title: `xhs comments` returns `code=-1` API error on two tested notes (v0.6.4)

[dengyilang-China]

Environment

• CLI: xiaohongshu-cli 0.6.4 (installed via uv tool install xiaohongshu-cli)
• Repo: jackwener/xiaohongshu-cli
• PyPI: 0.6.4 (no newer release available)
• OS: macOS 15.7.4
• Python: 3.11

Steps to Reproduce

1. xhs whoami --json → guest=false, cookie valid
2. xhs read <note_id> --json → ok=true, full note data returned
3. xhs comments <note_id> --json --xsec-token <token> → exit=1, api_error, code=-1
4. xhs comments <canonical_explore_url> --json --xsec-token <token> → same result

Expected Behavior

xhs comments should return comments for notes that are readable via xhs read.

Actual Behavior

{"ok": false, "error": {"code": "api_error", "message": "API error: {code: -1, success: false}"}}

Tested Scenarios

• Two different notes (both readable via xhs read; note_id obfuscated)
• Both canonical explore URL and note_id forms
• With --xsec-token (token verified working via xhs read)
• Environment without HTTP proxies
• Cookie valid (xhs whoami --json → guest=false)
• All command output redacted — no token or sensitive value exposed

Root Cause Assessment

xhs read works, but xhs comments → get_comments() at xhs_cli/client_mixins.py:388
calls _main_api_get("/api/sns/web/v2/comment/page", ...) which returns code=-1.
Likely the comments API endpoint or its request parameters no longer match the current
xiaohongshu API behavior. The available evidence does not yet distinguish an upstream
API change from a CLI request-signing, header, or parameter compatibility issue.

Adjacent Issues (not same fault)

• #60: notifications endpoints return API code=-1
• #62: sub-comments is unavailable

Suggested Fix

• Investigate get_comments() in xhs_cli/client_mixins.py (L388-442)
• Compare the /api/sns/web/v2/comment/page request against the working xhs read API call
• Check if request signature, headers, or payload format has changed