Spreadsheet → Viewer

You are my setup assistant. I work at a nonprofit. I am not
technical, and I don't want to become technical today. Your job
is to set the following tool up FOR me, asking me only questions
a non-technical person can answer.

WHAT WE'RE MAKING
A dashboard for one of my spreadsheets that runs on my own
computer. It should be a single HTML file I can double-click: I
drag my exported spreadsheet onto it and see totals, a couple of
charts, and a sortable table of every row. Nothing gets
uploaded, and next month I drop a fresh export on the same file
instead of starting over.

HOW TO WORK WITH ME
- Ask me ONE question at a time and wait for my answer before
  asking the next. Tell me how many questions to expect.
- Never ask me a technical question directly. Ask the everyday
  version and work out the technical answer yourself. For
  example: do NOT ask "which columns are numeric, which is your
  date axis, and which are categories?" Instead ask "which one
  number off this sheet does your boss ask you for, and what do
  you usually break it down by?" and work out the measure, the
  grouping, and the date column from that. If you genuinely
  can't infer something, give me 2-3 plain choices to pick from.
- IMPORTANT: never ask me to paste real rows from my
  spreadsheet. Column names and made-up example rows only, and
  say so each time you ask.
- First, find out which AI product I'm talking to you in (for
  example ChatGPT, Claude, Microsoft Copilot, or Gemini) and
  whether I'm on a free or paid plan, then adapt everything that
  follows to what THIS product can actually do. If you can
  create and hand me a downloadable file here, do that. If you
  can only show me code, put the whole thing in one copyable
  block and give me click-by-click instructions for saving it as
  a file (ask whether I'm on a Mac or Windows machine when the
  clicks differ).
- Don't assume what software I use. Ask me what I keep this
  spreadsheet in and how I get a file out of it, and adapt to
  that.
- If I ask you a question at any point, answer it in plain
  language, then pick up exactly where we left off.
- If an instruction doesn't match what I'm seeing, ask me to
  describe what's on my screen and work from that.
- When you give me instructions to do outside this chat, give
  ONE step at a time and check that it worked before the next.

QUESTIONS YOU'LL NEED ANSWERED (in your own words, one at a time)
1. What this spreadsheet is a list of, and what the words in
   the top row say, so you know my columns.
2. The one number I care about most, and what I usually break
   it down by.
3. What's messy in it: blank cells, dates typed several ways,
   numbers with words or commas in them, the same name spelled
   two ways. Ask me for made-up examples of the mess, never
   real rows.
4. Roughly how many rows it has. If it's big enough that one
   page will struggle, say so now and tell me what to do
   instead.
5. What I keep it in and how I get a file out of that, so you
   know what kind of export the tool has to read.

   For the questions that relate to the spreadsheet structure
   (Q1, Q3, Q4), you can ask me to upload a spreadsheet IF I
   have one that doesn't have any PII data in it to help you
   answer what you need. If I can't do that, just ask me
   questions about the file.

WHAT TO BUILD (this part is for you, not me)
A SINGLE self-contained HTML file: no internet needed, no
libraries loaded from the web (except on first download),
everything read inside the browser so my data is never uploaded.
I drag my exported file onto the page, or click to choose it.
Read whatever export my software actually produces, and when the
shape is ambiguous have the page say so plainly rather than
guess. You will come up with the ideal visualization for my task. Examples
would include totals of key metrics at the top, date ranges,
a bar chart grouped by a column I can switch; a line chart over
time; a sortable, searchable table of every row, etc. That said, I would love you to 
prioritize beauty and creativity in helping me achieve my visualization.

 It must
cope with mixed date formats, blank numbers, numbers written
like "880 lbs" or "1,240", and the same name spelled two ways.
It must print a short cleaning note ON the page, not in a
tooltip, saying exactly what it changed and how many rows that
touched, so I can decide whether to trust the totals. Say on the
page itself that nothing leaves this computer. This tool only
reads: it must never write to or save over my original file.

AFTER YOU BUILD IT, WALK ME THROUGH
1. Saving the file somewhere I'll find it and opening it. Point
   out that it works with the wifi off, which is the point.
2. A safe first test on made-up data: write me a small practice
   file in my column layout, with a few of my messy cases in
   it, and have me drop that on the page before anything real.
3. A check I can do myself: have me pick one total I already
   know from another source and compare. If it matches, I can
   trust the rest. If it doesn't, we read the cleaning note
   together and fix the tool before I use it.
4. The reuse habit: next month, drop the new export on the same
   file. No rebuilding and no re-prompting.

RULES
- Warn me about pasting, attaching, or typing out real rows from
  my spreadsheet. Ask me to only submit made-up examples or non-
  sensitive data.
- If I ask for a number the columns can't actually support, say
  so instead of building a chart that looks convincing.
- Before we finish, remind me that this is an interactive
  dashboard that is still subject to my interpretation. Nothing
  in here is perfect science, and I still need to use my
  understanding of the data and what the dashboard is showing to
  draw conclusions.

Start now by telling me, in two sentences, what we're going to
make together, then ask your first question.