feat(instrument): Port Semantic Kernel framework adapter (M2)

[mmercuri]

Summary

Ports the Microsoft Semantic Kernel framework adapter from the ateam
reference implementation onto the new layerlens.instrument base
layer. This is the M2 fan-out for Semantic Kernel — slicing it
out of the bundled M1.C agent-tier port (#97) so it can land
independently and be reviewed in isolation.

Source

• ateam/stratix/sdk/python/adapters/semantic_kernel/ (~929 LOC, 4
  files):
  • __init__.py (16 LOC)
  • lifecycle.py (594 LOC) — SemanticKernelAdapter + StratixMemoryStore
  • filters.py (259 LOC) — three SK filter implementations
  • metadata.py (60 LOC) — plugin / kernel metadata extraction
• Template: existing src/layerlens/instrument/adapters/frameworks/langchain/
  package layout, requires_pydantic guard, STRATIX* deprecation alias
  pattern.

Scope

• src/layerlens/instrument/adapters/frameworks/semantic_kernel/ —
  per-framework package (__init__, lifecycle, filters,
  metadata).
• src/layerlens/instrument/adapters/frameworks/__init__.py — lazy
  package marker; importing it does NOT pull in any framework SDK.
• tests/instrument/adapters/frameworks/test_semantic_kernel.py — 12
  SDK-shape mock tests (no real semantic-kernel runtime needed).
• samples/instrument/semantic_kernel/{main.py,README.md} — runnable,
  mocked-by-default sample.
• docs/adapters/frameworks-semantic_kernel.md — adapter integration
  guide (events emitted, capture config, BYOK pointer).
• pyproject.toml — adds semantic-kernel = ['semantic-kernel>=1.0,<2.0; python_version >= '3.10''] extra; ruff ARG002 ignore + pyright
  exclusions for frameworks/ (mypy --strict stays strict).

Naming + back-compat

• stratix.* import paths → layerlens.* import paths.
• Three filter classes renamed STRATIX* → LayerLens*. The old
  STRATIXFunctionFilter / STRATIXAutoFunctionFilter /
  STRATIXPromptRenderFilter symbols remain importable as deprecation
  aliases for ateam users (slated for removal next major SDK release).
• StratixMemoryStore class name preserved — it implements the SK
  memory store contract that users embed by name.

Base branch

The acceptance check (uv run pytest tests/instrument/adapters/frameworks/test_semantic_kernel.py -x)
imports from layerlens.instrument.adapters._base, which only exists
on feat/instrument-base-foundation (M1.A) — origin/main reverted
the instrument layer in #76 pending the M1 stack. This PR therefore
targets feat/instrument-base-foundation instead of main. It will
re-target to main once the M1.A foundation lands.

Blast radius

• Default pip install layerlens install set is unchanged.
  semantic-kernel is gated behind its own optional extra and a
  python_version >= '3.10' marker.
• No changes to existing public API surface beyond the new adapter
  package.
• Importing layerlens.instrument still does NOT pull
  semantic_kernel or any other framework module
  (tests/instrument/test_lazy_imports.py still passes).

Test plan

• uv run pytest tests/instrument/adapters/frameworks/test_semantic_kernel.py -x
  → 12 passed
• uv run mypy --strict src/layerlens/instrument/adapters/frameworks/semantic_kernel
  → Success: no issues found in 4 source files
• uv run ruff check src/layerlens/instrument/adapters/frameworks/semantic_kernel tests/instrument/adapters/frameworks/test_semantic_kernel.py
  → clean
• uv run pytest tests/instrument/test_lazy_imports.py tests/instrument/test_default_install.py
  → 6 passed (lazy-import + default-install guards still hold)
• uv run pytest tests/instrument/ → 62 passed, 1 skipped (no
  regressions vs. base-foundation)
• Reviewer (m-peko) verifies filter wiring + back-compat alias
  shape

Sibling of

• instrument: orchestration framework adapters (M1.C part 1) #96 feat/instrument-frameworks-orchestration (M1.C part 1)
• instrument: agent framework adapters (M1.C part 2) #97 feat/instrument-frameworks-agents (M1.C part 2) — this PR
  carves the SK slice out of instrument: agent framework adapters (M1.C part 2) #97 for independent review.