feat: implement property-driven lease increment automation

[iamtalib13]

What

This PR adds property-driven lease increment automation with item-level rules and daily execution.

Why

To automate future lease item amount revisions and reduce manual increment maintenance.

Changes

Data Model

• Added Property fields:
  • enable_auto_increment
  • increment_effective_from
  • increment_rounding_mode (Round, Ceil, Floor, None)
  • increment_rounding_precision
  • auto_create_lease_items_for_months
  • lease_increment_rules (Table)
• Added new child doctype: Lease Increment Rule
  • lease_item
  • increment_every
  • increment_uom (Month/Year)
  • increment_type (Percent/Amount)
  • increment_value
  • rule_effective_from
  • is_active

Backend

• Added propms/property_increment.py:
  • Property increment settings validation
  • Lease item increment generation engine
  • Supports percent and fixed-amount increments
  • Uses configured rounding mode/precision
  • Idempotent row generation (lease_item + valid_from)
  • Contextual Error Log entries on failures

Hooks & Scheduling

• Property validation hook:
  • propms.property_increment.validate_property_increment_settings
• Daily scheduler hook:
  • propms.property_increment.run_property_increment_engine

UI Guardrail

• In Property form, lease_increment_rules.lease_item now filters Items by:
  • item_group = "Lease Items"

Behavior

• Applies only to leases with lease_status = "Active" and docstatus < 2.
• Backdated active leases are considered, but generation is forward-only from current date.
• Requires existing base Lease Item rows in Lease for each configured rule item.

Validation

• Manual execute tested:
  • bench --site execute propms.property_increment.run_property_increment_engine
• Verified:
  • auto row creation works
  • increment math is correct
  • re-run is duplicate-safe
  • no runtime errors in tested flow

Commits

• feat(property): add lease increment settings to Property doctype
• feat(lease-increment-rule): define lease increment rule child table fields
• feat(increment-engine): implement property-driven lease item increment automation
• feat(hooks): wire property validation and daily increment scheduler
• feat(property): filter increment rule items to Lease Items group