release: v0.2.0 reliability, portability, and observability

[wryan2986]

Summary

Releases the reliability, portability, observability, and provider-abstraction work as v0.2.0.

Runtime correctness

• maxRetries now performs same-model retries for transient failures using exponential backoff and jitter
• omitted retry values use config.retry.max_retries through the public /feature and agent_loop paths
• provider-specific retry caps and retryable/non-retryable overrides are supported
• local/Ollama IDs without / resolve to the local provider and receive the configured local timeout
• worker execution no longer assumes /usr/local/bin/opencode
• portable executable-prefix arguments and OS-native checkpoint paths are supported

Durable budgets and paid-use controls

• persist token, cost, and workflow-call ledgers atomically across process/plugin restarts
• bound retained state by TTL and maximum task count
• cap parent orchestration with a 12-call workflow ceiling and 100-turn agent limit
• preserve terminal BUDGET_EXCEEDED behavior across all stages and failover paths
• explicitly report that precise parent-session token/dollar use is unavailable
• persist paid-fallback audit state and counters per project
• apply the global paid-call maximum over a rolling 24-hour window and expire stale task counters

Observability

• add a versioned JSON event schema and append-only JSONL event stream
• emit workflow, stage, attempt, retry, provider, budget, and completion events
• add recursive secret redaction and preserve legacy attempt/progress logs
• add a query utility for local audit and debugging

Provider adapters

• add a provider-adapter interface for identity, aliases, timeout keys, error normalization, and retry policy
• include built-in cloud and local adapters
• document and demonstrate custom adapters

Compatibility and platforms

• pin a known-supported OpenCode revision in config/supported-opencode.json
• verify patch application, Bun dependency installation, native standalone build, and source contracts in CI
• probe the moving upstream dev branch separately for patch drift
• test the portable runtime on Ubuntu, macOS, and Windows with Node 20 and 22
• test full validation on Node 18, 20, and 22
• add Windows/WSL/Git Bash and macOS documentation
• exercise the POSIX installer on every platform runner

Release and documentation

• update package version to 0.2.0 and policy schema version to 2.0.0
• update README, architecture, configuration, troubleshooting, roadmap, release notes, and examples
• add platform, provider-adapter, and event-logging guides

Validation

All required workflows passed on the final head:

• CI: Node 18, 20, and 22
• Cross-platform runtime: Ubuntu, macOS, and Windows on Node 20 and 22
• OpenCode patch compatibility: pinned revision patch check, dependency install, native build, and contract verification
• security scan, secret scan, environment-file rejection, agent permissions, routing policy, budget policy, feature contract, documentation links, deterministic tests, installer smoke tests, and bypass detection

Closes #5
Closes #6
Closes #7

[wryan2986]

Implementation and release validation are complete. The final head passed all required workflows: CI on Node 18/20/22, the Ubuntu/macOS/Windows runtime matrix on Node 20/22, security checks, installer smoke tests, and the pinned patched-OpenCode dependency install/native build/source-contract verification. The moving upstream dev probe also completed as a non-blocking compatibility report.

PR #15 is mergeable and ready to squash-merge. The only remaining blocker is the branch rule requiring one approving review from a reviewer with write access; there are currently no submitted reviews, and GitHub does not allow the PR author to approve their own PR.