fix: consolidate issue batch fixes

[guima-why]

Summary

This PR consolidates the recent GitHub issue batch fixes into a single commit.

It fixes the following issues:

• The search function is not working. #30: Make Ctrl+R conversation history search usable in the REPL, sourcing prompts from the persisted input history and agent context instead of an unsynchronized app-state message list.
• [Bug] Invalid --output-format causes unhandled ValueError traceback instead of user-friendly error #32: Return a friendly error for invalid --output-format values, avoid Python tracebacks, and accept case-insensitive output format values such as TEXT.
• [Bug] tree-sitter and tree-sitter-bash version constraints too loose, causing crash on bash tool invocation #33: Restore tree-sitter / tree-sitter-bash compatibility so bash parsing no longer crashes with Incompatible Language version 15. Must be between 13 and 14.
• [Bug] ! shell escape only provides autocomplete but does not execute the command #36: Make REPL ! shell escape commands execute locally instead of being sent as normal chat prompts.
• [Bug] Path traversal vulnerability in memory manager allows writing files outside memory directory #37: Reject memory names that attempt path traversal, such as ../escape, so memory writes cannot escape the configured memory directory.
• [Bug] Entire ~/.iac-code/ directory and sensitive files created with world-readable permissions #38: Ensure config, credentials, sessions, logs, image cache, and tool-result artifacts are created with owner-only file and directory permissions.
• [Bug] IAC_CODE_PROVIDER rejects documented provider names with spaces #39: Accept documented provider display names with spaces in IAC_CODE_PROVIDER, including OpenAPI Compatible.
• [Bug] Invalid --permission-mode is silently ignored and can auto-approve write tools in headless mode #40: Validate invalid --permission-mode values before entering the headless model/tool execution flow, with a localized friendly error and no traceback.
• [Bug] Headless --max-turns exits 0 instead of 2 when turn limit is reached #41: Return exit code 2 when headless execution stops because --max-turns is reached, including the deterministic --max-turns 0 path.
• [Feature] Add progress feedback for tool execution in headless text output mode #47: In headless text verbose mode, write tool progress events to stderr while keeping final text output on stdout for piping.
• [Bug] Multi-line input is split by line during history recall instead of being recalled as a whole #50: Store and replay multi-line prompts as one complete history entry instead of splitting them into separate lines or only replaying the final line.
• [Feature] Support Shift+Enter for newline in input prompt #51: Treat Shift+Enter as newline insertion in supported terminals instead of submitting the prompt.
• [Bug] Incompatible Language version 15. Must be between 13 and 14 #52: Prevent Terraform generation/parsing flows from failing with the tree-sitter ABI mismatch error.
• [Bug] iac-aliyun skill is unlikely to be auto-loaded when using certain models #53: Auto-trigger the bundled iac-aliyun skill for Alibaba Cloud IaC prompts, including prompts that use the Chinese variant 模版 as well as 模板.

The PR also updates i18n catalogs for new user-facing validation messages so the added errors remain translatable, and documents the new REPL shell escape and multi-line input behavior in the website docs.

Verification

• make translate
• make format
• make lint
• make test (3777 passed, 244 warnings)
• npm run build from website/
• Additional post-rebase review checked that messages.po translations were preserved and that the rebase did not introduce semantic regressions.

Notes

• PR is based on origin/main.
• The local-only docs commit from local main was intentionally excluded from this PR.