data(wallets): add optional keyExportFormats column, seed Pera from first-party support docs (DBIP #3725)

[foxxx009]

Closes #3725 (data side)

Problem

No field records which documented backup artifacts (mnemonic, raw private key, encrypted backup) a wallet can export; the keyExport boolean alone cannot answer migration questions.

Changes

• Appended the optional keyExportFormats column to all 92 wallet tables (22 → 23 columns, CRLF preserved).
• Seeded one verified Algorand cell, per the DBIP's "begin with a small verified Algorand subset":
  • listings/specific-networks/algorand/wallets.csv → pera → ["encrypted-backup","mnemonic"] from Pera's first-party support docs: backing up your recovery passphrase (mnemonic) and Pera's Algorand Secure Backup import/export workflow (password-protected encrypted backup).
  • Pera has no canonical offer row, so the documented value lives on the existing algorand listing override (DBIP §Scope rule 3).
• All other cells left blank (not yet verified). Nothing inferred from custodial = FALSE, hardware = TRUE or keyExport = TRUE.
• MetaMask is documented in the DBIP motivation but deferred here: its Secret Recovery Phrase / imported-account distinction needs offer-granularity scoping (§Scope rule 4) and the DBIP scopes the initial seed to Algorand.
• No actual keys, mnemonics or backup files are included, per §Scope rule 6.

Verification

• All 92 files rectangular: 22 → 23 columns; exactly one non-empty cell (algorand/pera), parsing to the documented array
• keyExport boolean values untouched everywhere
• validate_csv.py → csv_to_json.py → validate.py all green locally
• Generated algorand.json carries pera.keyExportFormats = ["encrypted-backup","mnemonic"] and columns.wallets includes the new key
• Schema/validator side lives in the paired tools PR (base json-tools); CI on this PR will stay red until that lands (same pattern as feat(mcpservers): selfHostedEnvVarTypes schema, column metadata and validation (DBIP #3683) #3698+feat(mcpservers): add selfHostedEnvVarTypes column, classify Filecoin Onchain Cloud PRIVATE_KEY (DBIP #3683) #3699, feat(apis): optional structured requestLimits column (DBIP #3724, tools side) #3738+data(apis): add optional requestLimits column, document Alchemy HTTP batch limit (DBIP #3724) #3737)

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