Feat/wasm poc

[rzofchak-a2ai]

added wasm bindings to spackle commands to recreate spackle::Project::generate() done in typescript in the aggregate (insert moneyball gif here)

WASM.md contains a claude-generated rundown of all the changes. but generally:

• wasm support added with wasm-bindgen
• in-memory renditions of functions to support wasm exports for host-driven i/o
• added small poc ts file that loads wasm, reads fixture project temaplates, and validates/renders. then evaluates hook plans
• table-driven tests

run just poc to get poc output:

Loading WASM module...
WASM module loaded.

=== parse_config ===
  Name: (unnamed)
  Slots: 3
  Hooks: 2
    slot: slot_1 [String]
    slot: slot_2 [Number]
    slot: slot_3 [Boolean]
    hook: hook_1 → echo hook_1 output
    hook: hook_2 → echo hook_2 output

=== validate_config ===
  Config is valid.

=== validate_slot_data ===
  Slot data is valid.

=== Reading .j2 template files ===
  Found 5 template(s):
    bad.j2 (21 bytes)
    {{slot_2}}.j2.j2 (386 bytes)
    {{slot_1}}.j2 (386 bytes)
    subdir/bad.j2 (22 bytes)
    subdir/{{slot_1}}.j2 (386 bytes)

=== render_templates ===
  ERROR bad.j2: bad.j2: Error rendering contents: Failed to render 'bad.j2'
  {{slot_2}}.j2.j2 → 42.j2
    hello\n42\ntrue\n\nEu anim consequat est labore tempor do magna aliqua aute consectetur.\nPariatur enim c...
  ERROR subdir/bad.j2: subdir/bad.j2: Error rendering contents: Failed to render 'subdir/bad.j2'
  subdir/{{slot_1}}.j2 → subdir/hello
    hello\n42\ntrue\n\nEu anim consequat est labore tempor do magna aliqua aute consectetur.\nPariatur enim c...
  {{slot_1}}.j2 → hello
    hello\n42\ntrue\n\nEu anim consequat est labore tempor do magna aliqua aute consectetur.\nPariatur enim c...

=== Writing to output ===
  Wrote 3 file(s).

=== evaluate_hooks ===
  hook_1: WOULD RUN
    cmd: echo hook_1 output
  hook_2: WOULD RUN
    cmd: echo hook_2 output

Done.