feat: add fetchCanisterLogs method to PocketIc

[yasumorishima]

Summary

Adds a fetchCanisterLogs() method to the PocketIc class, implementing the fetch_canister_logs management canister query call.

This allows users to programmatically retrieve canister log records, which is especially useful for debugging traps in timers and heartbeats that are otherwise invisible.

Closes #68

Changes

• management-canister.ts: Add Candid IDL types, TypeScript interfaces, and encode/decode functions for fetch_canister_logs
• pocket-ic-types.ts: Add FetchCanisterLogsOptions and CanisterLogRecord public types
• pocket-ic.ts: Add fetchCanisterLogs() method that makes a query call to the management canister with effectivePrincipal set to the target canister
• main.mo: Add print_log method to test canister for testing
• fetchCanisterLogs.spec.ts: Add 2 test cases (fetch logs after Debug.print + empty logs for fresh canister)

Implementation notes

• Follows the same pattern as the Rust library implementation
• Uses effectivePrincipal: { canisterId } as required by the IC spec for management canister queries
• The caller must be a controller of the target canister (anonymous principal is rejected)
• Maps timestamp_nanos to timestampNanos in the public type to follow the project's camelCase convention

Test plan

• pnpm run build passes
• pnpm run test:pic — all 13 tests pass (11 existing + 2 new)
• pnpm run format:check passes
• e2e tests pass (Node.js + Bun, ubuntu + macos)

[Copilot]

Pull request overview

This PR adds first-class support in the PocketIc client for retrieving canister log records via the management canister fetch_canister_logs query, enabling programmatic access to logs useful for debugging timers/heartbeats.

Changes:

• Added Candid IDL encode/decode and TypeScript types for the management canister fetch_canister_logs API.
• Introduced public FetchCanisterLogsOptions and CanisterLogRecord types and a new PocketIc.fetchCanisterLogs() method using effectivePrincipal: { canisterId }.
• Added a test-canister print_log method and new Jest tests validating log retrieval and the empty-logs case.

Reviewed changes

Copilot reviewed 7 out of 9 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
packages/pic/src/management-canister.ts	Adds IDL record types and encode/decode helpers for fetch_canister_logs.
packages/pic/src/pocket-ic-types.ts	Exposes new public option/record types for the feature.
packages/pic/src/pocket-ic.ts	Implements PocketIc.fetchCanisterLogs() and maps response fields to public types.
packages/pic/tests/src/fetchCanisterLogs.spec.ts	Adds coverage for fetching logs and handling empty logs.
packages/pic/tests/test-canister/main.mo	Adds print_log method to emit log output from the test canister.
packages/pic/tests/test-canister/test_canister.did	Updates DID to include the new print_log method.
packages/pic/tests/test-canister/declarations/test_canister.did.js	Regenerates JS DID bindings including print_log.
packages/pic/tests/test-canister/declarations/test_canister.did.d.ts	Regenerates TS DID typings including print_log.

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