fix(categorization): connect card descriptors to counterparty history (#1095)

* fix(categorization): connect card descriptors to counterparty history

suggest_categories returned no signal for recurring card merchants
(reported: Anthropic booked to 5420 fourteen times, zero suggestions).
Three compounding causes, all fixed:

- normalizeCounterpartyName() now reduces card-network descriptors to
  their merchant segment ("ANTHROPIC* CLAUDE SUB SAN FRANCISCO" ->
  "anthropic"; "PAYPAL *SPOTIFY" -> "spotify"), so monthly per-charge
  tails stop splintering one merchant into unmatchable variants. SQL
  mirror normalize_counterparty_key() updated in lockstep (migration
  20260721140000), keeping the ledger-context template join exact.
- New token_subset match tier bridges templates learned from manual
  bookings ("Claude Dec" -> "claude") to bank descriptors containing
  the token, and card-core descriptors to legacy splintered templates.
  Guarded by a distinctive-token filter so generic/geo words never
  match on their own.
- Merchant history falls back to description when merchant_name is
  null: card purchases never carry merchant_name, so the history path
  was structurally blind to exactly the transactions that need it.
  History keys now share the counterparty-template normalization and
  the 200-row window is ordered by recency.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(categorization): guard single-token matches, anchor history on original_description

Review follow-ups (CodeRabbit on #1095):

- token_subset tier: a single shared distinctive token now also requires
  occurrence_count >= 3 on the template, so a template named after a
  common word or first name (one prior booking) cannot vacuum up
  unrelated transfers ("SWISH ANDERS JOHANSSON"). Multi-token agreement
  stays unrestricted; the Claude/Anthropic case (14 bookings) is
  unaffected.
- merchant history keys on original_description ?? description: the raw
  bank descriptor is immutable while description is a user-editable
  working title, so renaming a transaction no longer severs its history
  link for future recurring charges.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* chore(migrations): re-timestamp card-descriptor migration after prod moved past it

Prod applied 20260721144311 (#1101) through 20260721201747 (#1104) while
this PR was open; 20260721140000 would sort before them and risk being
skipped by out-of-order auto-apply at merge. Not yet applied to prod, so
renaming is safe; the preview branch re-applies idempotently
(CREATE OR REPLACE).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

lib/transactions/__tests__/category-suggestions.test.ts

@@ -46,6 +46,40 @@ describe('buildMerchantHistory / merchantHistoryFor', () => {
     expect(merchantHistoryFor(map, 'Unknown Vendor')).toEqual({})
     expect(merchantHistoryFor(map, null)).toEqual({})
   })
+
+  it('falls back to the description when merchant_name is null (card purchases)', () => {
+    // Bank feeds only carry counterparty names for transfers; card purchases
+    // arrive with merchant_name null and the merchant buried in a descriptor
+    // whose tail (product, city) changes between charges. All of these are
+    // one counterparty: the reported Anthropic no-signal bug.
+    const map = buildMerchantHistory([
+      { merchant_name: null, description: 'ANTHROPIC* CLAUDE SUB SAN FRANCISCO', category: 'expense_software' },
+      { merchant_name: null, description: 'ANTHROPIC*CLAUDE SUB +14155551234', category: 'expense_software' },
+      { merchant_name: 'Anthropic', description: 'irrelevant when merchant_name set', category: 'expense_software' },
+    ])
+    expect(merchantHistoryFor(map, null, 'ANTHROPIC* CLAUDE SUB LONDON')).toEqual({
+      expense_software: 3,
+    })
+    expect(merchantHistoryFor(map, 'Anthropic')).toEqual({ expense_software: 3 })
+  })
+
+  it('anchors on original_description so user renames do not sever history', () => {
+    // description is a mutable working title; a user renaming the row to
+    // "Software" must not detach it from the raw bank descriptor identity.
+    const map = buildMerchantHistory([
+      {
+        merchant_name: null,
+        description: 'Software',
+        original_description: 'ANTHROPIC* CLAUDE SUB SAN FRANCISCO',
+        category: 'expense_software',
+      },
+    ])
+    expect(merchantHistoryFor(map, null, 'ANTHROPIC*CLAUDE SUB +14155551234')).toEqual({
+      expense_software: 1,
+    })
+    // Renamed title itself is NOT a key when the raw descriptor exists.
+    expect(merchantHistoryFor(map, null, 'Software')).toEqual({})
+  })
 })
 
 describe('getSuggestedCategories: counterparty history', () => {