feat(icp): add chat-based ICP creation and edit interface

[Rishavraaj]

Summary

Before this PR, creating or editing an ICP profile used a form sheet with dropdowns. It was rigid — you had to know exactly what filters to pick. Now you just describe your ideal customer in plain English and AI builds the filters for you.

• You type something like "SaaS companies in India, 50–500 employees, targeting CTOs using Salesforce"
• AI converts that into structured Apollo search filters
• It shows you a preview with how many contacts match
• You confirm, give the profile a name, and it's saved

Editing works the same way — the Edit button now opens the same chat, but pre-loaded with existing filters. You can say "add Bengaluru" or "also target VPs" and it merges your change in without losing anything.

Changes

New chat interface

• IcpChat component — a chat window that walks you through describing your ICP, reviewing filters, and saving the profile
• /icps/new — new page that opens the chat for creating a profile
• /icps/:id/edit — new page that opens the chat pre-filled with existing filters for editing

Smarter filter refinement

• When you ask to change something (e.g. "add Bengaluru"), the AI gets the current filters as context so it merges your request instead of starting from scratch. Previously it would drop everything and only return what you just said.
• AI now classifies your reply as "confirm" or "change something" — so any natural phrasing works, not just specific keywords like "yes" or "confirm"

Profile detail panel

• Edit button navigates to the chat edit page instead of opening a sheet
• Now shows all filters: company name, excluded locations, job titles, seniority levels, technologies

Removed contact DB sync

• The "Run ICP" button and the endpoint behind it are removed
• Contacts are fetched live from Apollo's free search endpoint — no credits used, no DB writes needed

Fixed Apollo search bugs

• Company location filter was sending to the wrong Apollo field (person_locations → organization_locations)
• Company name filter and excluded locations were missing from the contacts search payload — this was causing 28M contacts to be returned instead of the expected few hundred

Test plan

• Go to /icps/new, describe an ICP, confirm filters, name it, verify profile is created and you land on the profile page
• Open a profile → click Edit → chat opens with existing filters shown → say "also target VPs" → verify VP title is added and other filters are kept
• Say something vague to confirm ("looks good", "save it", "yes") — verify it saves
• Say something vague to refine ("tweak the location") — verify it asks for more info instead of saving
• Profile detail panel shows all filter types (location, titles, seniority, tech, excluded locations)
• Contacts tab returns a reasonable count (not 28M) when company name filter is set