CLI missing: agents update command — cannot update agent capabilities after registration

[newjordan]

Problem

After registering an agent with --capabilities 1, attempting to claim a task that requires --capabilities 7 fails with:

AnchorError thrown in src/instructions/claim_task.rs:255.
Error Code: InsufficientCapabilities. Error Number: 6003.
Error Message: Agent has insufficient capabilities.

The agent's on-chain PDA already exists, so re-running agents register fails with AgentAlreadyRegistered. There is no CLI subcommand to update the agent's capabilities.

What I expected

Either:

1. agents register --reuse or agents update --capabilities 7 to update the existing agent PDA, OR
2. agents register with --capabilities flag should call update_agent if the agent already exists (idempotent upsert)

What's available in the protocol

The protocol IDL (@tetsuo-ai/protocol v0.2.1) has a working update_agent instruction:

name: "updateAgent"
args: [
  { name: "capabilities", type: { option: "u64" } }
  { name: "endpoint",     type: { option: "string" } }
  { name: "metadata_uri", type: { option: "string" } }
  { name: "status",       type: { option: "u8" } }
]

All args are Option<T>, so a minimal update would be capabilities: Some(7). But the CLI has no agents update subcommand to call this.

Reproduction

1. agenc-marketplace --network mainnet agents register --authority <key> --agent-id <id> --capabilities 1 ... — succeeds, agent PDA created
2. Attempt to claim a task with --capabilities 7 — fails InsufficientCapabilities
3. Re-running agents register with --capabilities 7 — fails AgentAlreadyRegistered
4. No agents update command exists to call update_agent

Environment

• CLI: agenc-marketplace v next (binary, standalone)
• Network: mainnet
• Protocol: HJsZ53Zb27b8QMRbQpuDngE44AdwCGxvEZr61Zmxw1xK
• Node: v22

Suggested fix

Add an agents update subcommand that calls the existing update_agent instruction, e.g.:

agenc-marketplace --network mainnet agents update \
  --authority <key> \
  --agent-id <id> \
  --capabilities 7