fix(goals): address AI review on PR #1798 (CodeRabbit + Codex)

Correctness:
- GoalPledge#matches? rejects outflows on transfer pledges so a +$200
  purchase no longer satisfies a $200 deposit pledge after .abs
- GoalsController#sync_linked_accounts! saves through the goal so
  currency/depository/family validations actually run on update
- AlreadyClaimedError replaces empty RecordInvalid in resolve_with! and
  reconciler rescues the dedicated class
- SweepExpiredGoalPledgesJob wraps each expire! in a per-record rescue
- Assistant::Function::CreateGoal disambiguates duplicate account names
  and returns an absolute URL via mailer host config
- Family#savings_inflow_velocity defensively scopes from the family's
  accounts (was Account.joins(:goal_accounts).where(goal_id: ...))
- GoalPledgesController#set_goal preloads linked_accounts + providers
  to drop the N+1 on any_connected_account?
- Stepper subtitle update walks to the enclosing dialog before
  querySelector so two stepper instances don't fight over one header
- categories/_form.html.erb data-action targets color-icon-picker, not
  the non-existent "category" controller

UX / visual:
- Projection chart drops preserveAspectRatio="none" and pins endDate at
  today for past-due goals so the today marker stays in-domain
- _color_picker / categories form swap non-standard border-1 for border
- Goals index search input uses ring-alpha-black-100 (was raw gray-500)

Refactors:
- Goal#header_summary extracts the multi-line ERB header block
- Goal#catch_up_delta_money sums open_pledges in SQL
- Goal#projection_summary uses I18n.l for the on-track month label
- Account#default_pledge_kind moves the manual/transfer decision out of
  GoalPledgesController
- GoalPledge::Reconciler iterates ordered (created_at, id) so first-claim
  wins is deterministic under non-sequential PKs
- Goals::FundingAccountsBreakdownComponent + Goals::AccountStackComponent
  use clamp(0..) instead of Float::INFINITY / [x, 0].max
- Goals::StatusPillComponent#label provides a titleize fallback
- Goal projection chart skips the redundant initial _draw and reuses
  the snapped point in the past branch (no double-bisect)
- Goal pledge preview drops maximumFractionDigits: 0 so USD/EUR show
  cents while JPY/KRW stay whole-unit
- Demo generator captures the Wedding fund goal in the seed loop
  instead of looking it up by hardcoded name

Tests:
- GoalPledgeTest: outflow rejection
- GoalsControllerTest: cross-currency attachment rejected on update
- SweepExpiredGoalPledgesJobTest: cancelled coverage + per-record rescue
- GoalTest: pledge_action_label_key flips to manual_save without an
  unconditional guard

app/javascript/controllers/goal_stepper_controller.js

@@ -204,8 +204,11 @@ export default class extends Controller {
       this.stepperLineTarget.classList.toggle("border-subdued", this.currentStep === 1);
     }
     // Modal subtitle lives in the dialog header, outside this controller's
-    // DOM scope. Locate it by attribute and update directly.
-    const subtitle = document.querySelector('[data-goal-stepper-modal-subtitle]');
+    // DOM scope. Walk up to the enclosing dialog first so two stepper
+    // instances on the same page (eg. edit modal opened over the new modal)
+    // each update their own header rather than the first match in the DOM.
+    const dialog = this.element.closest("dialog, [role='dialog']");
+    const subtitle = (dialog || document).querySelector("[data-goal-stepper-modal-subtitle]");
     if (subtitle) {
       subtitle.textContent =
         this.currentStep === 1 ? this.step1SubtitleValue : this.step2SubtitleValue;