Simplify policy identification: use name as primary identifier; remove ID from policies

[v0lkan]

SPIKE policies currently have both an ID (UUID) and a name field, which adds unnecessary complexity.

In comparison, HashiCorp Vault policies use only a name as the unique identifier. Following the same approach will provide simplicity and better UX.

Current Behavior

SPIKE policies have two identifiers:

• ID: Auto-generated UUID (e.g., 550e8400-e29b-41d4-a716-446655440000)
• name: User-provided name (e.g., database-policy)

This creates ambiguity:

• Which identifier should users use for spike policy get?
• Which identifier appears in logs and audit trails?
• Users must track both values or look up one from the other

Expectation:

Use name as the sole unique identifier for policies.
Remove the ID field from db schema.

# Create policy with unique name
spike policy create database-policy --spiffeid-pattern "..." --path-pattern "..."

# Reference by name only
spike policy get database-policy
spike policy delete database-policy

Rationale

1. Simplicity: One identifier is easier to remember and use than two
2. Vault compatibility: Users familiar with Vault will expect this pattern
3. Human-readable: Names are meaningful; UUIDs are not
4. Fewer moving parts: No need to generate, store, or index UUIDs
5. Better UX: spike policy get database-policy is clearer than spike policy get 550e8400-e29b-41d4-a716-446655440000