Adds three new read-only tools the chat LLM can call to answer
"who/what did the most X" questions that previously fell through
the cracks:
- rank_top_customers — ranks customers by invoiced_total, paid_total,
invoice_count, or outstanding_balance over a named time period
- rank_top_items — ranks catalog items by quantity_sold or revenue
- rank_expense_categories — ranks expense categories by total spend
All three share a new ResolvesPeriod trait that centralizes the
period-name → [start, end] logic. GetCompanyStatsTool is refactored
onto the same trait (identical public schema — the 'all_time' option
is only exposed on the new ranking tools, where an unbounded window
makes sense; stats over "all time" collapses every record into one
giant bucket and is rarely useful).
Each tool follows the existing pattern: snake_case name, one-sentence
description tuned for LLM tool selection, JSON-schema parameters
with injected company scoping (never trusting LLM-supplied company
IDs), and JSON-encodable output. outstanding_balance on the customer
tool explicitly ignores the period param since it's a current-state
snapshot.
Multi-company scoping tests lock down the session-authoritative
boundary on every new tool. Per-metric ordering tests verify the
aggregate queries actually rank correctly, and an ad-hoc-item
exclusion test verifies rank_top_items skips invoice lines where
item_id is null (free-typed entries that have no catalog row to
rank by id).
15 new tests added (tests/Feature/Ai/Tools/); test suite grows from
398 to 413 passing. LLM tool count goes from 9 to 12 — the model
will discover the new tools automatically via the function-calling
schema with no prompt changes required.
