feat(piggy): piggy list/add/remove (v0.6.0)HEADv0.6.0master

New `piggy` group:
- `piggy list` lists piggy banks with saved/target amounts and linked
  accounts.
- `piggy add|remove <name|id> <amount> [--account NAME]` changes the
  saved amount on a linked account via PUT /piggy-banks/{id}.

Firefly syncs the whole account list on that PUT, so every linked account
is resent (others without current_amount, which keeps their value) or it
would be unlinked. Removing below zero is rejected before any write, and
the saved amount is read back so a refused add fails loudly instead of
returning 200 unchanged.

add/remove currently hit an upstream bug on Firefly III <= 6.7.9:
PiggyBankFactory::linkToAccountIds passes the pivot current_amount (an int
from the DB) to bcsub() uncast, so any PUT with "accounts" 500s
(firefly-iii/firefly-iii#13063). Documented in SKILL.md/README; the live
integration test skips on that error and runs once upstream is fixed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/README.md b/README.md
index c6cdb80..ee575b0 100644
--- a/README.md
+++ b/README.md
@@ -77,6 +77,9 @@ firefly budget disable <name|id> mark a budget inactive
 firefly budget delete <name|id> --yes
 firefly budget limit-list <name|id>
 firefly budget limit-set <name|id> --amount N [--start D] [--end D]
+firefly piggy list
+firefly piggy add <name|id> <amount> [--account A]
+firefly piggy remove <name|id> <amount> [--account A]
         [--currency CODE]
 
 firefly category list
@@ -102,6 +105,8 @@ The command set grows over time; see `CLAUDE.md` for how to add one.
   a period; `budget limit-set` sets a spending limit over a date range.
   `budget update` renames a budget or edits its auto-budget fields.
   `budget delete` and `tx delete` require `--yes`.
+- Piggy banks: `piggy add/remove` change the saved amount on a linked account.
+  Blocked on Firefly III <= 6.7.9 by upstream bug firefly-iii/firefly-iii#13063.
 
 ## For agents (skill)