feat: per-component resource handle tables for 3-component chains

[avrabe]

Problem

When fusing 3+ component chains with re-exported resources (e.g., `resource_floats`), the P2 wrapper's canonical `resource.new` returns sequential indices (1, 2, 3...) that are incompatible with wit-bindgen 0.52.0's internal `ResourceTable` slab, which expects 4-byte-aligned memory pointers as handles.

Root Cause

wit-bindgen re-exporting components manage resources via an internal slab in linear memory:

• Handles are heap pointers (4-byte aligned addresses from `Box::into_raw`)
• The slab validates handles with `value & 3 == 0`
• Sequential canonical indices fail this check

Fix

Implement per-component handle tables as i32 arrays in each re-exporter's linear memory. Handles are byte offsets into the array (always 4-byte aligned). The P2 wrapper routes re-exporter resource operations to these custom functions instead of canonical types.

Implementation Plan

See `docs/superpowers/plans/2026-03-29-per-component-handle-tables.md` on branch `feat/per-component-handle-tables`.

Current Progress (on branch)

• Identify re-exporter components in resolver
• Merger $N suffix stripping for resource_rep/new_by_component
• Caller [resource-rep] synthesis for borrow params
• Adapter callee_defines=false no-conversion path

Remaining Work

• Allocate handle table space in merger #70 Allocate handle table space in merger
• Generate handle table wasm functions in fused module #71 Generate handle table wasm functions
• Route re-exporter resource imports to handle table functions (P2 wrapper) #72 Route re-exporter resource imports to handle table functions (P2 wrapper)
• Fix adapter caller_already_converted for re-exporter chains #73 Fix adapter caller_already_converted for re-exporter chains
• Re-enable resource graph definer propagation (targeted) #74 Re-enable resource graph definer propagation
• Promote resource_floats and resource_with_lists to runtime tests #75 Promote resource_floats to runtime test