WIP: profile phonebook write contracts

[MarcLeinenDE]

Adds a hard-gated physical research profiler for the next complete-SDK-coverage block.

Scope of the profiler:

• synthetic local phonebook group create/update/delete
• synthetic local contact create/update/delete
• bounded candidate matrix for the still-incomplete move_contacts_to_group.contacts representation
• read-back verification after every operation
• best-effort finally cleanup targeting only IDs/names created by the profiler

Evidence basis before the run:

• NR2301 public API already marks the methods live-verified/admin-accessible but several nested write payloads remain incompletely normalized
• related Marvell backend/frontend source confirms addnew_pb / update_pb fields location,index,name,mobile,home,office,email,group as string-shaped wire values and delete_pb fields location,count,indexarray
• group write top-level keys are already documented upstream

Safety/privacy:

• requires NR2301_WRITE_INTEGRATION=1
• uses only generated synthetic local groups/contact values
• does not print existing contact names, numbers or addresses
• does not touch SIM contacts
• USB management mode is not involved

WIP until the physical lifecycle has run and the resulting exact contracts are normalized upstream before permanent high-level SDK helpers are added.