fix(contacts): add view action, show phones in list, preserve fields on update

[holden093]

Summary

Fixes three gaps in the manage_contacts agent tool that made phone-number workflows unreliable: list now includes phone numbers, a new view action returns full contact details by UID, and update preserves existing emails/phones when the caller doesn't pass them (preventing data loss on partial edits like renaming).

Target branch

• This PR targets dev, not main.

Linked Issue

Fixes #4747

Type of Change

• Bug fix (non-breaking — fixes a confirmed issue)

Checklist

• I searched open issues and open PRs — this is not a duplicate.
• This PR targets dev
• My changes are limited to the scope described above — no unrelated refactors or whitespace changes mixed in.
• I actually ran the app (docker compose up or uvicorn app:app) and verified the change works end-to-end. Type-checks and unit tests are not enough.

How to Test

1. Add a contact with name, email, and phone number via the UI or CardDAV.
2. Ask the agent to "list my contacts" — verify phone numbers appear in the output.
3. Ask the agent to "view contact [name]" — verify full details (phones, address, UID) are shown.
4. Ask the agent to "rename [contact] to [new name]" — verify the phone and email are preserved after the update.

Visual / UI changes

None — backend-only change.

[vdmkenny]

Good direction (phones in list, the view action, and preserving fields on rename are all real gaps), but the preserve logic still loses data on partial single-field updates, which is the common case it is meant to cover.

The existing-contact fetch only runs when emails, email, and phones are all absent:

existing = None
if "emails" not in args and "email" not in args and "phones" not in args:
    rows = await asyncio.to_thread(cc._fetch_contacts)
    existing = next((r for r in rows if r.get("uid") == uid), None)
...
if "phones" in args:
    phones = [...]
else:
    phones = list(existing.get("phones") or []) if existing else []

So update {uid, emails:["new@x"]} with no phones takes the else branch while existing is still None, and phones get wiped. Same in reverse: passing only phones wipes the emails. The data loss it claims to prevent still happens whenever the caller updates one of the two fields.

Fix: fetch existing whenever either field is missing (or just always on update), then fall back per-field independently:

existing = None
if "emails" not in args and "email" not in args or "phones" not in args:
    rows = await asyncio.to_thread(cc._fetch_contacts, True)
    existing = next((r for r in rows if r.get("uid") == uid), None)

Two smaller things:

• The preserve fetch uses _fetch_contacts() (cache, force=False), so a contact added moments earlier may be missing from the cache, giving existing=None and the same wipe. view already passes force=True; do the same here.
• Please add a test: rename-only keeps both emails and phones; updating only emails keeps the existing phones (and vice versa). That pins exactly this bug.

list/view/phones changes are fine as-is.

[holden093]

Addressed all three issues, @vdmkenny:

1. Preserve guard fixed — changed the condition from AND to OR: fetch the existing contact whenever either emails or phones is missing, not only when both are absent. Single-field updates like {uid, emails:[new]} now correctly preserve the other field.

2. Force-refresh on preserve fetch — switched _fetch_contacts() to _fetch_contacts(True) so a just-added contact is not missed by a stale cache.

3. Tests added — four tests in test_contacts_update_preserve.py covering: rename-only keeps both emails and phones, emails-only update preserves phones, phones-only update preserves emails, and explicit both-fields overwrites without a fetch. All pass.