feat(agent-bridge): add editV2 method with correct field names

[hnshah]

Fixes #22

Problem

The editV2() method was missing from the agent bridge client, and there was a field name mismatch between client expectations and server reality.

Server expects (from server/agent-edit-v2.ts):

• baseRevision (number)
• operations (array of block operations)

What was missing:

• No editV2() method in the bridge client
• No TypeScript types for edit v2 operations

Solution

This PR adds:

✅ EditV2Input interface with correct field names matching the server
✅ EditV2BlockOp union type covering all 6 operation types:

• replace_block
• insert_after
• insert_before
• delete_block
• replace_range
• find_replace_in_block

✅ editV2() client method that POSTs to /documents/:slug/edit/v2
✅ Idempotency-Key header support (auto-set from input.idempotencyKey)

Usage

const bridge = createAgentBridgeClient({ baseUrl, auth: { shareToken } });

await bridge.editV2(slug, {
  by: 'ai:my-agent',
  baseRevision: 128,
  operations: [
    { op: 'replace_block', ref: 'b3', block: { markdown: '# Updated' } },
    { op: 'insert_after', ref: 'b3', blocks: [{ markdown: '## New section' }] }
  ],
  idempotencyKey: crypto.randomUUID()
});

Testing

• ✅ Field names match server implementation
• ✅ All operation types from server/agent-edit-v2.ts are covered
• ✅ Idempotency header automatically included when key provided
• ✅ Follows existing bridge client patterns

Related

• Resolves the API mismatch described in EditV2Input type sends wrong field names — revision/ops vs server's baseRevision/operations #22
• Aligns client types with docs/agent-docs.md examples
• Makes edit v2 (the recommended editing approach) actually usable from the bridge client