chore(spp_programs): remove dead cycle_base.py (never imported, stale duplicate of cycle.py)

[gonzalesedwin1123]

Summary

spp_programs/models/cycle_base.py is dead code: it has never been imported in spp_programs/models/__init__.py (checked back to the initial v2 export, 4da8e30e). The live spp.cycle model is defined in spp_programs/models/cycle.py; cycle_base.py is a stale near-duplicate (~700 lines) that defines the same _name = "spp.cycle" but is never loaded by Odoo.

$ grep -n "cycle" spp_programs/models/__init__.py
from . import cycle
from . import cycle_membership
# no cycle_base

Why it matters

• It misleads readers and tooling. Issue fix(spp_programs): spp.cycle.total_amount_in_words renders amount in English regardless of user/record language #236 linked its root cause to cycle_base.py:128-135 — the dead file — while the live bug is the identical code in cycle.py. PR fix(spp_programs): locale-aware total_amount_in_words (#236) #300 patched the right file, but only after untangling this; the dead copy still carries the hardcoded lang="en" bug and will keep matching greps.
• Divergence is already real: cycle_base.py declares currency_id with a company-currency default, while the live cycle.py has it related to program_id.currency_id (store=True). Anyone reading the wrong file gets the wrong model.
• Dead model code inflates code-analysis noise and translation extraction surface.

Proposed fix

Delete spp_programs/models/cycle_base.py. Before deleting, diff it against cycle.py to confirm nothing in it is newer than the live implementation (spot-check suggests it's an older snapshot, but the diff should be part of the PR description).

No manifest version bump strictly needed if we treat unloaded files as non-functional, but per convention a micro bump + HISTORY note is cheap and keeps the audit trail clean.

Found while

Reviewing PR #300 / issue #236 (locale-aware total_amount_in_words).