feat(miner-hands): Agent-SDK CodingAgentDriver (query() loop)

[JSONbored]

A second implementation of the CodingAgentDriver interface (#4262, must land first), this one driving the coding agent in-process via the Claude Agent SDK's query() function rather than shelling out to a CLI binary. Verified via grep -rn "claude-agent-sdk\|@anthropic-ai" package.json packages/*/package.json — zero matches. Neither @anthropic-ai/claude-agent-sdk nor any @anthropic-ai/* package is a dependency anywhere in this repo today (root package.json, packages/gittensory-engine/package.json, packages/gittensory-mcp/package.json, packages/gittensory-miner/package.json are all clean). This issue adds the dependency.

Deliverables

• Add @anthropic-ai/claude-agent-sdk as a dependency of the package hosting this driver (likely packages/gittensory-engine, matching feat(miner-hands): define the CodingAgentDriver interface seam #4262's src/miner/ home) and wire an implementation around its query() async-iterable loop.
• Map query()'s streamed message/tool-use events into the CodingAgentDriver result shape from feat(miner-hands): define the CodingAgentDriver interface seam #4262 — success/failure, changed files, transcript/usage summary — without leaking SDK-specific event types into the shared interface.
• Respect the same scoped-working-directory and acceptance-criteria-file inputs feat(miner-hands): define the CodingAgentDriver interface seam #4262's interface defines, so a caller (the iterate-loop orchestrator in maintainer-only issue maintainer: local create->score->self-review iterate-loop orchestrator (the control-flow core) #2333) can swap this driver for the CLI-subprocess driver (feat(miner-hands): CLI-subprocess CodingAgentDriver (reuse SpawnFn/redactSecrets/EFFORT_TIMEOUT_MS pattern) #4266, this batch) with no caller-side changes — that interchangeability is the entire point of the shared interface.
• A tool-call interception point compatible with what the PreToolUse hook maintainer-only issue maintainer: PreToolUse-hook-enforced house rules (deny even under bypassPermissions) #2343 describes ("a PreToolUse hook registered against the CodingAgentDriver's underlying session that intercepts every tool call BEFORE execution") — maintainer: PreToolUse-hook-enforced house rules (deny even under bypassPermissions) #2343 names this driver's SDK session as its intended hook attachment point, so the SDK's own hook/callback surface needs to be reachable from outside this module, not fully encapsulated.
• Tests using the SDK's own test/mock affordances (or a thin injected wrapper around query() if none exists) so CI never makes a real model call — mirroring the injected-SpawnFn testability convention feat(miner-hands): define the CodingAgentDriver interface seam #4262 establishes for the CLI-subprocess driver.

References

• Verified via grep -rn "claude-agent-sdk\|@anthropic-ai" package.json packages/*/package.json — zero hits repo-wide, confirming this is a net-new dependency
• Depends on feat(miner-hands): define the CodingAgentDriver interface seam #4262 (this batch) — the CodingAgentDriver interface this implements
• Issue maintainer: PreToolUse-hook-enforced house rules (deny even under bypassPermissions) #2343 (maintainer-only, "PreToolUse-hook-enforced house rules") — names this driver's SDK session as the exact hook attachment point; coordinate on the hook surface shape
• Issue maintainer: local create->score->self-review iterate-loop orchestrator (the control-flow core) #2333 (maintainer-only, "iterate-loop orchestrator") — the intended caller of both driver implementations, confirming interchangeability with feat(miner-hands): CLI-subprocess CodingAgentDriver (reuse SpawnFn/redactSecrets/EFFORT_TIMEOUT_MS pattern) #4266 is a hard requirement

[linear-code]

JSO-3254