Standardize rule endpoint client identification and remove Basic Auth

[bracyw]

Description

Rule endpoints use three different patterns for client identification: Basic Auth headers (add_rule, delete_rule), path parameters (get_all_rules_with_client_info), and JSON body (subscribe, unsubscribe). Standardize on one approach and remove the Basic Auth dependency.

Depends on PR #555 merging first.

Acceptance Criteria

• add_rule and delete_rule no longer use Basic Auth
• All rule endpoints use consistent client_id pattern (path param or body)
• TypedHeader<Authorization> removed from rule_controller.rs
• Frontend rules.api.ts updated to match

Proposed Solution

Replace Basic Auth extraction with path parameters in rule_controller.rs, matching get_all_rules_with_client_info. Update routes in main.rs and API calls in rules.api.ts.