Please update app/lia_ure.py so that appointment handling behaves in two different ways:

1) DIFFERENTIATE BETWEEN SPECIFIC AND VAGUE TIMES

Right now detect_appointment_confirmation() treats everything as a confirmed appointment.

Change this so that we have two helpers:

- is_specific_time(body_lower: str) -> bool
- is_vague_time_window(body_lower: str) -> bool

Use the following logic:

- A message is a SPECIFIC time if it contains:
  - a clock pattern like "10:30", "9:00", "14:15", or
  - a number + am/pm (e.g. "10am", "3 pm"), or
  - a day word plus "at" followed by a number (e.g. "Saturday at 10", "Tuesday at 3").

- A message is a VAGUE time window if:
  - it contains a day word (monday–sunday, tomorrow, next week, this weekend, later today)
  - AND a time-of-day word like "morning", "afternoon", or "evening"
  - BUT does NOT contain any explicit time digits.

For example:
- "Can I do Tuesday afternoon?" → VAGUE
- "How about Saturday at 10:30?" → SPECIFIC

You can keep using DAY_WORDS, TIME_OF_DAY, RELATIVE_WORDS and TIME_REGEXES from the previous change.

2) UPDATE generate_lia_reply TO USE THESE TWO CASES BEFORE OTHER HANDLERS

At the top of generate_lia_reply(), after checking opted_out, add:

- If is_specific_time(body_lower) is True:
    - Treat this as a CONFIRMED APPOINTMENT and EARLY RETURN.
    - Use a confirmation message like:

      raw_name = customer_state.get("customer_name")
      name = raw_name if raw_name else "there"

      reply = (
          f"Thanks {name} – I’ve booked you in for {inbound_text.strip()} at Lincoln Audi.\n\n"
          "I’ll send you a reminder beforehand and let you know who your point of contact will be when you arrive.\n\n"
          "If anything changes, just drop me a quick message here and I’ll be happy to move it."
      )

      (You can improve the string slightly by stripping extra words, but using inbound_text is fine for now.)

    - Update state:

      customer_state["appointment_status"] = "BOOKED"
      customer_state["appointment_confirmed_text"] = inbound_text
      customer_state["appointment_confirmed_at"] = datetime.now(timezone.utc).isoformat()
      customer_state["last_message"] = inbound_text
      customer_state["last_reply_type"] = "APPOINTMENT_CONFIRMED"

    - RETURN reply, customer_state immediately so we don’t fall through to other logic.

- Else if is_vague_time_window(body_lower) is True:
    - This means the customer has suggested a day + morning/afternoon/evening but no specific time.
    - Do NOT mark the appointment as booked yet.
    - Instead, send a reply offering two specific time options:

      raw_name = customer_state.get("customer_name")
      name = raw_name if raw_name else "there"

      reply = (
          f"No problem, {name} – that time works.\n\n"
          "I’ve got two slots available: 1:00pm or 4:00pm.\n\n"
          "Which would suit you better?"
      )

    - Update state:

      customer_state["appointment_status"] = "INVITED"  # still waiting for exact time
      customer_state["last_message"] = inbound_text
      customer_state["last_reply_type"] = "APPOINTMENT_TIME_CHOICES"

    - RETURN reply, customer_state immediately.

3) FALLBACK APPOINTMENT DETECTION

- You can keep detect_appointment_confirmation() as a wrapper that simply calls is_specific_time().
- All other logic (small talk, direct questions, tiers) should only run if neither of the above early-return cases fired.

4) NAME FALLBACK

- Make sure everywhere we build the name, we use:

  raw_name = customer_state.get("customer_name")
  name = raw_name if raw_name else "there"

- So we never see "Unknown" in replies.

5) Run `python -m app.lia_ure` after the changes to ensure the module still executes its test block without errors.