feat(fusion_clock): bi-weekly attendance filter — pay-period filters + picker

Reuse the existing Pay Period setting (Frequency + Anchor) as the single
source of truth via a shared pure helper (models/pay_period.py); fusion.clock.report
delegates to it. Add Current/Previous/Next Pay Period filters to the attendance
search view (search-method computed booleans on hr.attendance), a Bi-Weekly Period
picker wizard (pick start -> auto +2 weeks, editable; Apply opens the filtered list)
reachable from an Attendance menu item and a dashboard tile. Window follows the
configured frequency; TZ-correct via local-day boundaries. Bump 3.14.4 -> 3.15.0.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

fusion_clock/wizard/clock_period_picker_views.xml

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="utf-8"?>
+<odoo>
+
+    <record id="view_fusion_clock_period_picker_form" model="ir.ui.view">
+        <field name="name">fusion.clock.period.picker.form</field>
+        <field name="model">fusion.clock.period.picker</field>
+        <field name="arch" type="xml">
+            <form string="Bi-Weekly Period">
+                <sheet>
+                    <div class="alert alert-info" role="alert">
+                        Pick the period start — the end auto-fills to one pay period later
+                        (two weeks by default). Adjust either date, then click
+                        <b>View Attendances</b>.
+                    </div>
+                    <group>
+                        <field name="date_start"/>
+                        <field name="date_end"/>
+                    </group>
+                </sheet>
+                <footer>
+                    <button name="action_apply" string="View Attendances" type="object" class="btn-primary"/>
+                    <button special="cancel" string="Cancel" class="btn-secondary"/>
+                </footer>
+            </form>
+        </field>
+    </record>
+
+    <record id="action_fusion_clock_period_picker" model="ir.actions.act_window">
+        <field name="name">Bi-Weekly Period</field>
+        <field name="res_model">fusion.clock.period.picker</field>
+        <field name="view_mode">form</field>
+        <field name="view_id" ref="view_fusion_clock_period_picker_form"/>
+        <field name="target">new</field>
+    </record>
+
+</odoo>