Move terminal emulator to daScript

[borisbat]

Summary

• move terminal parsing, screen state, scrollback, UTF-8 handling, input encoding, replies, snapshots, and viewport projection from C++ to daScript
• keep only the raw OS PTY/process transport in native code
• expose raw array<uint8> feed/write/reply paths while retaining compatibility string boundaries
• replace native semantic tests with inspectable daScript coverage and retain a transport-only ConPTY integration test
• add feed-throughput and snapshot-scaling benchmarks

Performance

For a 154 KB / 2,000-line feed workload:

• JIT feed: about 42-47 ms -> 9-10 ms
• transient strings: 300,000 -> 95
• full snapshot with ~10k history rows: about 133-156 ms -> 8.7 ms
• viewport projection remains history-independent at roughly 0.3-0.4 ms

The feed benchmark includes terminal creation, parsing, scrollback allocation, and disposal. Viewport projection is cached by terminal revision and scroll offset, so it is rebuilt on updates rather than for idle frames.

Validation

• in-tree formatter: 6 changed daScript files verified
• lint: 6 files, 0 issues, 0 errors
• modules/dasTerminal/tests/snapshot_smoke.das
• modules/dasTerminal/tests/terminal_semantics.das
• embedded dasImgui terminal compile-only check
• transport-only ConPTY test: 8/8 assertions
• focused Release builds for shared/static terminal modules and tests-cpp-small

Companion UI adaptation: borisbat/dasImgui#228

Deliberately deferred oracle phase

This PR does not select or embed a C++ terminal library. The follow-up sequence is:

1. audit existing terminal libraries and compare their semantics/features against this implementation;
2. select the oracle and document gaps/normalization rules;
3. only then build side-by-side replay for deterministic test streams;
4. after synthetic parity is understood, compare captured real PTY streams.

[Copilot]

Pull request overview

This PR migrates the dasTerminal terminal emulator (parsing, state, snapshots, key/paste encoding, and viewport projection) from C++ into daScript, leaving native code as a minimal PTY/process transport layer. It replaces the prior C++ semantic test coverage with daScript tests and adds benchmarks around feed throughput and snapshot scaling.

Changes:

• Remove the C++ terminal emulator implementation and expose only PTY transport primitives from native code.
• Implement the terminal emulator, snapshots, and input encoding in modules/dasTerminal/daslib/terminal.das, with new daScript semantic tests.
• Adjust tests/benchmarks/docs to reflect the new raw-byte transport boundary and daScript-centric validation.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests-cpp/small/test_terminal.cpp	Reduces C++ coverage to a PTY transport-only ConPTY integration test, now matching raw-byte behavior.
modules/dasTerminal/tests/terminal_semantics.das	Adds daScript semantic coverage for parsing/snapshots/chunk invariance/replies/events/key+paste encoding.
modules/dasTerminal/tests/snapshot_smoke.das	Updates smoke test expectations around disposal semantics.
modules/dasTerminal/src/terminal.h	Removes the C++ terminal emulator API/types (deleted).
modules/dasTerminal/src/terminal.cpp	Removes the C++ terminal emulator implementation (deleted).
modules/dasTerminal/src/dasTerminal.cpp	Refactors native bindings to expose PTY-only APIs and a pty_handle managed type.
modules/dasTerminal/src/aot_builtin_terminal.h	Replaces TerminalHandle with PtyHandle and updates exported native entrypoints.
modules/dasTerminal/README.md	Updates module documentation to describe daScript emulator + native PTY boundary and new test/benchmark locations.
modules/dasTerminal/daslib/terminal.das	Introduces the daScript terminal emulator core, snapshots/viewports, and raw-byte reply/event plumbing.
modules/dasTerminal/CMakeLists.txt	Removes C++ terminal sources, installs only PTY headers, and registers the new daScript semantic test.
benchmarks/terminal/snapshot_scaling.das	Adds a feed-throughput benchmark alongside existing snapshot scaling benchmarks.

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[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated no new comments.