fix(codemode): simplify activity cards and retain command previews

[tt-a1i]

Problem

Collapsed Code Mode cards still show script output and spill paths, hiding useful activity behind noise. They only show a few nested calls and replace the others with more calls, while running rows add status dots and repeated running labels. Long Bash commands disappear when Pi's 200-character JSON argument preview cuts through the command string; short-enough commands can instead fill a very wide terminal row.

Value

Make every recorded call visible and identifiable at a glance, using the same tool icons as ordinary OpenPI tools. Keep the default view quiet and compact horizontally, with detailed script/output evidence available through native expansion.

Approach

• Show every recorded call once, in original order; remove recent/salient call selection and more calls placeholders.
• Hide script output and full-output paths until expansion.
• Reuse ordinary tool activity Codicons while retaining success, error, cancellation and unknown markers.
• Use muted text for running cards/rows, without compact running dots or repeated running labels. Expanded evidence retains explicit running status.
• Cap Bash command previews at 80 terminal columns, including the truncation ellipsis. Narrow terminals reduce that budget further; reserve room for status/error/timing facts. Read paths continue to follow the row width.
• Retain the verified string prefix of Pi's native 197-character-plus-... argument previews, dropping incomplete escapes/dangling high surrogates and marking the missing suffix rather than guessing it.
• Decode outer output JSON only when expanded; preserve raw results, terminal sanitization, native image rendering, and recorded bounded arguments.
• Update README and renderer/native integration regression coverage.

Validation

Head: 6cd057a6d74092945e06dda57092e0bb635d467b; based on main at d96b9fcc7ed4116b090c300b103b612056e34fc3.

• bun run check: passed on the final working tree.
• node --test --experimental-strip-types tests/extensions/codemode-display/*.test.ts: 22 passed. The repository SDK exercises the older-host safe no-op fallback for renderer registration.
• The same native fixture was additionally run against the locally installed Pi 1.0.2 host through a temporary import-remapping wrapper: 1 passed, exercising the public renderer resolver, pending/completed transitions, expansion and native images.
• git diff --check: passed.
• Coverage includes all-call ordering (5/20/100 calls), quiet muted running state, all result states, immutable native results, expanded evidence, the 80-column Bash cap for ASCII/CJK and all statuses, narrow terminals, long native argument previews, escape/Unicode truncation, failure/cancellation markers and terminal-control stripping.

Latest bun run test run: not green — 2,303 tests, 2,292 passed, 2 failed, 0 cancelled, 9 skipped. Both remaining failures are in tests/extensions/plan-mode/result-rendering.test.ts (a rich plan renders without throwing and keeps its content, expanded survives edge-content plans at extreme widths); both also failed before these changes. Other earlier runs additionally reported setup/workflow/worktree timing failures, which this change does not claim to fix. The final test-only lint adjustment replaced an expression-bodied assertion callback with a block; check and targeted/native tests were rerun afterward.

The full runner stopped on its Node-test failures, so this is not a claim that every later runner phase passed. Final interactive TUI appearance after /reload has not yet been manually verified.

Impact

• User-visible behavior: every recorded call is shown, output/path evidence is collapsed, familiar tool icons are reused, running state is muted, Bash preview length is bounded to 80 columns.
• Model-visible context/tools: none; native executors, schemas, permissions, model-facing results and tool activation are unchanged.
• Runtime/lifecycle: none; presentation-only resolver, no extra hooks or execution state stores.
• Persisted config/data: none; no new preferences or migrations.
• Compatibility/risk: older hosts retain the native fallback. Call-card height now grows with the recorded ledger, intentionally, rather than hiding calls. Preview recovery is specific to Pi's current 200-character format and fails closed on unrecognized/malformed data. Font requirements remain the same as ordinary tool icons. Expanded nested arguments are still native bounded previews, not reconstructed full commands.

[tt-a1i]

独立子代理审查

审查范围：d96b9fcc7ed4116b090c300b103b612056e34fc3 → 6cd057a6d74092945e06dda57092e0bb635d467b，覆盖本 PR 的 5 个变更文件及相关上下文。

安全、正确性与设计

• [信息] 未发现可证实、可操作的安全漏洞、明显逻辑错误或回归问题；没有需要自动修复的条目，也没有待决策的架构/风格建议。
• Critic 阶段无候选问题可筛选；这不等于保证不存在缺陷。

验证与覆盖限制

• [信息] 专项测试 22 项、仓库 check、Pi 1.0.2 native wrapper smoke，以及该冻结 head 的 19 项 GitHub checks 通过，均为父代理提供的验证证据，不冒充子代理独立执行。
• [信息] 无 .smartcr 规则库，已按无规则模式审查。AST 未产出问题，但缺少 TypeScript grammar，因此不声称 AST 覆盖通过。
• [信息] 未独立验证真实交互 TUI 或其他宿主版本；仓库旧 SDK 的 native 测试 no-op 不能替代新宿主验证，CI 全绿也不能替代手工界面验收。

本次没有修改代码；不自动批准、不自动合并。