The goal of this PR is to improve performance when doing the backfill of
daily usages by avoiding creating fees with 0 units on customer usage
for charge filters.

Here is an example for a single subscription linked to 24 billable
metrics with 2 filters.
Only 37 daily usages have been created.

**Before:**

```
Benchmark.bm do |x|
  x.report("FillHistoryService:") do
    DailyUsages::FillHistoryService.call!(subscription: s, from_datetime: DateTime.new(2025, 5, 1))
  end
end

user     system      total        real
FillHistoryService: 31.097790   1.076836  32.174626 ( 64.291435)
```
Took 64.29s

**After:**

```
Benchmark.bm do |x|
  x.report("FillHistoryService:") do
    DailyUsages::FillHistoryService.call!(subscription: s, from_datetime: DateTime.new(2025, 5, 1))
  end
end

user     system      total        real
FillHistoryService: 20.107554   0.743215  20.850769 ( 41.683220)
```
Took 41.68s

## Context

In many places of the application, we are defining a `boundaries`
object, sometimes as an instance of a `Hash`, sometimes as an
`OpenStruct`. The fields are not always the same and since the
boundaries are injected in a lot of services, this causes some
uncertainty when accessing the properties.

## Description

In an attempt to improve the readability and the reliability of this key
part of the application, the goal of this PR is to introduce a new
`BillingPeriodBoundaries` class and to use it everywhere in replacement
of `Hash` and `OpenStruct`.

It should also improve the memory consumption as OpenStructs are known
to cause memory issues in Ruby when YJIT is enabled

…calculation (#4124)

## Context

The `current_usage` endpoint is frequently called across the
application. Adding the projected usage calculation was causing
significant memory spikes due to the high request volume, impacting
application performance.

By moving the expensive calculation to a dedicated endpoint, we ensure
that fetching basic usage remains fast and stable, while still providing
the projection data when it's explicitly needed. This resolves the
memory issues and improves overall stability.

## Description

Creates a new endpoint, `GET
/customers/:external_customer_id/projected_usage`, to handle the
computationally intensive projected usage calculation.

Reverts the existing `/customers/:external_customer_id/current_usage`
endpoint to its original, lightweight state by removing the projection
logic.

## Context

Currently fees on one-off invoices does not contain billing period

## Description

As part of the `quotes` feature, the decision is to add billing period
on one-off invoice. This information would be consumed by analytics
since it would allow splitting revenue across the billing interval

---------

Co-authored-by: Alexandre Monjol <alexandre.monjol@gmail.com>

## Description

We need to add a new field for NetSuite invoice creation: `item_source`

## Problem
You can't filter by any plan attribute and have a search term. 

## Steps to reproduce
Add a filter to plan/subscription and a search term. 
```SubscriptionsQuery.call(organization:, filters: {overriden: true}, search_term: "Mario")```

This would produce this query
```
Subscription Count (0.5ms) SELECT COUNT(*) FROM (SELECT 1 AS one FROM
"subscriptions" INNER JOIN "customers" ON "customers"."id" =
"subscriptions"."customer_id" INNER JOIN "plans" "plan" ON "plan"."id" =
"subscriptions"."plan_id" WHERE "subscriptions"."organization_id" = $1
AND ((((((((("subscriptions"."id"::varchar ILIKE '%Mario%' OR
"subscriptions"."name" ILIKE '%Mario%') OR "subscriptions"."external_id"
ILIKE '%Mario%') OR "plans"."name" ILIKE '%Mario%') OR "plans"."code"
ILIKE '%Mario%') OR "customers"."name" ILIKE '%Mario%') OR
"customers"."firstname" ILIKE '%Mario%') OR "customers"."lastname" ILIKE
'%Mario%') OR "customers"."external_id" ILIKE '%Mario%') OR
"customers"."email" ILIKE '%Mario%') AND "plan"."parent_id" IS NULL
LIMIT $2 OFFSET $3) subquery_for_count [["organization_id",
"034de852-b25c-41c5-9f58-a8f07bdcd2bd"], ["LIMIT", 25], ["OFFSET", 0]]
```

but fails with 
```
(lago-api):8:in '<main>': PG::UndefinedTable: ERROR: invalid reference
to FROM-clause entry for table "plans" (ActiveRecord::StatementInvalid)
LINE 1: ..."subscriptions"."external_id" ILIKE '%Mario%') OR
"plans"."n...
                                                             ^
HINT:  Perhaps you meant to reference the table alias "plan".
```

Ramsack calls the table `plans` as `plans` and in our query, we are calling `plan`. 

## Fix
Call the `plans` table as `plans` just like Ramsack, without an alias.
```
SELECT COUNT(*) FROM (SELECT 1 AS one FROM "subscriptions" INNER JOIN
"customers" ON "customers"."id" = "subscriptions"."customer_id" INNER
JOIN "plans" ON "plans"."id" = "subscriptions"."plan_id" WHERE
"subscriptions"."organization_id" = $1 AND
((((((((("subscriptions"."id"::varchar ILIKE '%Mario%' OR
"subscriptions"."name" ILIKE '%Mario%') OR "subscriptions"."external_id"
ILIKE '%Mario%') OR "plans"."name" ILIKE '%Mario%') OR "plans"."code"
ILIKE '%Mario%') OR "customers"."name" ILIKE '%Mario%') OR
"customers"."firstname" ILIKE '%Mario%') OR "customers"."lastname" ILIKE
'%Mario%') OR "customers"."external_id" ILIKE '%Mario%') OR
"customers"."email" ILIKE '%Mario%') AND "plans"."parent_id" IS NULL
LIMIT $2 OFFSET $3) subquery_for_count [["organization_id",
"034de852-b25c-41c5-9f58-a8f07bdcd2bd"], ["LIMIT", 25], ["OFFSET", 0]]
```

)

## Problem
An organization can't query ActivityLogs older than 30 days. 
The number 30 days is hardcoded in the code. 

## Fix
Add an attribute on `Organization` called `audit_logs_period` and use
this as the period allowed to query the Activity Logs. When `nil`, it
should not limit query.

## Context

This PR intend to improve the performance when creating an event using
the `POST /api/v1/events`.

The event model has a uniqueness validation on the transaction_id field.
Rails is performing a database query to validate this uniquess and it
appears to be slow...

## Description

Since we already have a unique index in place in the database, this PR
removes the validation and adds the logic to catch the Postgres error.
Some load testing have been conducted with this approach and it cuts the
response time by a large factor, increasing the number of events/sec
that could be received by the API

Error: Different expressions with the same alias
difference:\ntoDecimal128(25., 26) AS difference\nand\ntoDecimal128(15.,
26) AS difference\n: While processing toDecimal128(25., 26) AS
difference.

…te mutation (#4126)

## Roadmap Task

👉
https://getlago.canny.io/feature-requests/p/allow-add-ons-to-be-added-to-subscription-invoices

👉
https://getlago.canny.io/feature-requests/p/define-quantities-for-plan-charges

 ## Context

 What is the current situation?

 **Option 1:** User has to create a one off invoice alongside the
 subscription, it will create 2 different invoices.

 **Option 2:** User can add a recurring billable metric and use event to
 have this fee invoice on subscription renewal, but it won’t appear on
 the first billing subscription.

 What problem are we trying to solve?

 At subscription creation or afterward, there is no clear way to invoice
 a fixed fee that is not tied to events, aside from the subscription fee
 itself. This fee could be either a one-time charge or a recurring one.

 ## Description

Update Plans::Create mutation and Plan resolver to include fixed charges
data,
  also, adds all required graphql types.

## Context

We need a service to update fixed charge and cascade-update. When
updating a fixed charge, we can't change `pay_in_advance` and `prorated`
`display_name` can only be changed in parent fixed_charge (not updated
while cascade)
`charge_model` can only be updated if plan is not attached to any
subscription
`properties` can be updated while cascading only if before update
current fixed_charge and the child had matching properties
`taxes` can be changed only for parent fixed_charge without attached
subscription

## Description

- added `FixedCharges::UpdateService`

#4122)

## Problem
List the customers that has N active subscriptions.
## Fix
Adding the `active_subscriptions_count_from` and
`active_subscriptions_count_to` to `CustomersResolver`.
This will be used to filter the active subscriptions for the customers.