feat(ads): asset extension tools + RSA update + conversion-action mgmt

[illia-sapryga]

Summary

Three logical chunks bundled here because they share ads/write.py's dispatch + apply infrastructure and would conflict at the file level if split into separate PRs.

1. Asset extension tools (call asset, location asset, ad schedule, geo exclusions, image assets, customer-scope refactor of callouts/sitelinks/snippets, promotion management, asset linking)
2. RSA in-place update (update_responsive_search_ad)
3. Conversion-action management (3 new tools — create / update / remove)

Depends on #33 (dynamic Google Ads enum introspection) — please merge that first.

What's added

1. Asset extension tools

Tool	Purpose
draft_call_asset	Campaign or customer scope, E.164 phone normalization, ad-schedule restriction, optional conversion-action override. Verified against BGI Tint (+19164609257).
draft_location_asset	Google Business Profile-backed LOCATION_SYNC AssetSet, with label/listing filters
draft_image_assets	Campaign image extensions from local files with MIME + dimension validation
draft_callouts	Refactored to support BOTH campaign-scope AND customer-scope (the account-level CustomerAsset path that propagates to every eligible campaign automatically)
draft_sitelinks	Same dual-scope refactor + URL reachability check + char-limit validation
draft_structured_snippets	Same dual-scope refactor
add_ad_schedule	Mon–Sat 8am–9pm-style scheduling via AdScheduleInfo CampaignCriterion
add_geo_exclusions	Negative geo CampaignCriterion records to shrink a broad include list
link_asset_to_customer	Promote existing Asset rows from campaign-scope to account-level (CustomerAsset) — for re-using shared logos / sitelinks across campaigns
update_call_asset / update_sitelink / update_callout	In-place asset updates with FieldMask — only the fields the caller passes are modified
draft_promotion / update_promotion	PromotionAsset create + swap (PromotionAsset is immutable, so 'update' is implemented as create-new-link-old-unlink atomically)
_apply_assets()	Shared helper routing a populate-fn through either CampaignAsset or CustomerAsset linkage based on scope
_normalize_phone_e164()	E.164 phone-number normalization with US/CA + EU trunk-prefix handling

2. RSA in-place update

Tool	Purpose
update_responsive_search_ad	Update existing RSAs without delete-then-recreate. Partial update via FieldMask — only the fields the caller passes are modified. Headlines/descriptions accept either bare strings (unpinned) or {\"text\": ..., \"pinned_field\": \"HEADLINE_1\"} dicts (pinned).

3. Conversion-action management (3 new tools)

Tool	Purpose
draft_create_conversion_action	Create AD_CALL / WEBSITE_CALL / WEBPAGE / WEBPAGE_CODELESS / GOOGLE_ANALYTICS_4_CUSTOM / etc. with value, threshold, attribution model, counting type
draft_update_conversion_action	Partial update via FieldMask — rename / promote-to-Primary / demote-to-Secondary / set value / change duration threshold / change attribution
draft_remove_conversion_action	Irreversible removal. Warns that SMART_CAMPAIGN_* and GOOGLE_HOSTED types reject mutation with MUTATE_NOT_ALLOWED (Google manages those).

The 3 conversion-action tools live in their own module adloop/ads/conversion_actions.py and route through _execute_plan's dispatch via lazy-import _apply_*_conversion_action_route shims.

Refactors (uses #33's enum_names())

The _VALID_TYPES, _VALID_CATEGORIES, _VALID_COUNTING_TYPES, _VALID_ATTRIBUTION_MODELS sets in conversion_actions.py are pulled dynamically from the SDK via enum_names(). Same for _VALID_PROMOTION_OCCASIONS, _VALID_DISCOUNT_MODIFIERS, _VALID_CALL_REPORTING_STATES in ads/write.py.

The hardcoded versions of those sets had drifted from the SDK. The ConversionActionTypeEnum set was missing 29 of 40 valid values; PromotionExtensionOccasionEnum was missing 2.

Validated end-to-end

This batch was used to build out a real Google Ads account end-to-end (BGI Tint, customer 8202753856):

• Created 1 search campaign, 6 ad groups, 150 keywords, 6 RSAs, 22 account-level CustomerAssets (sitelinks/callouts/snippets/promotions/call/business logo), 20 campaign image extensions, 2 negative shared lists
• Created 2 conversion actions (Calls from Ads (≥90s) AD_CALL @ $250, Website Call (GFN ≥90s) WEBSITE_CALL @ $250 with 90s threshold) and bound them to a custom conversion goal
• Updated existing call asset to point at the new AD_CALL conversion with USE_RESOURCE_LEVEL_CALL_CONVERSION_ACTION
• Updated 2 existing promotion assets in place

Test plan

• Full suite passes: uv run pytest → 430/430 tests
• tests/test_ads_extensions.py — comprehensive validation + apply-handler tests for every new function (uses fake services mirroring the google-ads SDK protos; no network)
• tests/test_conversion_actions.py — 29 tests covering validation, partial update mask, FieldMask correctness, MCP registration
• tests/test_update_rsa.py — RSA update integration tests
• _apply_* handlers verified to emit the right FieldMask paths via fake service inspection
• Promotion swap: verified that creating-new + linking-new + unlinking-old happens atomically against fake services

Known follow-ups (out of scope for this PR)

• Older hardcoded enum sets in ads/write.py (_VALID_BIDDING_STRATEGIES, _VALID_CHANNEL_TYPES, _VALID_DAYS_OF_WEEK, _VALID_HEADLINE_PINS, etc.) could be migrated to enum_names() in a separate refactor PR.
• update_call_asset allows full-list replacement of ad_schedule_targets but no append-mode — append would be useful for some workflows.