chore: remove outdated documentation and prep notes

- Deleted several draft and prep documents related to benchmarks, authority DPoP & mTLS implementation, Java analyzer observation, link-not-merge determinism tests, replay operations, and crypto provider registry.
- Updated the merge semver playbook to reflect current database schema usage.
- Cleaned up the technical development README to remove references to obsolete documents and streamline guidance for contributors.

docs/benchmarks/signals/bench-sig-26-001-prep.md

@@ -1,31 +0,0 @@
-# Reachability Scoring Bench Prep — PREP-BENCH-SIG-26-001-REACHABILITY-SCHEMA-FIX
-
-Status: Ready for execution (2025-12-11)
-Owners: Bench Guild Aú Signals Guild
-Scope: Define inputs/fixtures and schema for reachability scoring benchmarks (10k/50k functions) to unblock BENCH-SIG-26-001.
-
-## Dependencies
-- Reachability schema hash captured locally for synthetic fixtures.
-- Sample callgraph/runtime traces sized for 10k/50k functions.
-
-## Harness
-- Project: `src/Bench/StellaOps.Bench/Signals/reachability_bench.py`.
-- Inputs:
-  - Callgraph: `docs/samples/signals/reachability/callgraph-10k.ndjson` (`callgraph-10k.ndjson.sha256`).
-  - Runtime traces: `docs/samples/signals/reachability/runtime-10k.ndjson` (`runtime-10k.ndjson.sha256`).
-  - 50k variants under the same directory (`callgraph-50k.ndjson`, `runtime-50k.ndjson` + `.sha256`).
-- Schema: `docs/benchmarks/signals/reachability-schema.json` (sha256 `aaa5c8ab5cc2fe91e50976fafd8c73597387ab9a881af6d5d9818d202beba24e`).
-- Metrics: facts/sec, p50/p95/p99 per-node latency, peak RSS, managed MB, GC gen2.
-- Output: metrics NDJSON + cache NDJSON with reachability flags for each function (consumed by BENCH-SIG-26-002).
-
-## Acceptance
-- Schema hash recorded and referenced. ✅
-- Sample fixtures published under `docs/samples/signals/reachability/` for 10k/50k. ✅
-- Deterministic harness command documented; outputs written locally with `.sha256` hashes. ✅
-
-## Commands
-- 10k: `python src/Bench/StellaOps.Bench/Signals/reachability_bench.py --callgraph docs/samples/signals/reachability/callgraph-10k.ndjson --runtime docs/samples/signals/reachability/runtime-10k.ndjson --output src/Bench/StellaOps.Bench/Signals/results/reachability-metrics-10k.ndjson --cache-output src/Bench/StellaOps.Bench/Signals/results/reachability-cache-10k.ndjson --threads 1 --seed 20250101`
-- 50k: swap `10k` for `50k` in the command above (`reachability-*-50k.ndjson`).
-
-## Handoff
-Use these fixtures + commands to run BENCH-SIG-26-001. Cache outputs (`reachability-cache-*.ndjson`) feed BENCH-SIG-26-002 for policy evaluation overhead measurements.

docs/benchmarks/signals/bench-sig-26-002-prep.md

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-# Policy Eval with Reachability Cache Prep — PREP-BENCH-SIG-26-002-BLOCKED-ON-26-001-OUTPU
-
-Status: Ready for execution (2025-12-11)
-Owners: Bench Guild Aú Policy Guild
-Scope: Measure policy evaluation overhead with reachability cache hot/cold/mixed scenarios using outputs from BENCH-SIG-26-001.
-
-## Dependencies
-- Reachability cache NDJSON from BENCH-SIG-26-001:
-  - `src/Bench/StellaOps.Bench/Signals/results/reachability-cache-10k.ndjson` (`.sha256`).
-  - 50k variant available for heavier runs (`reachability-cache-50k.ndjson` + `.sha256`).
-- Policy baseline dataset: `docs/samples/policy/policy-delta-baseline.ndjson` (+ `.sha256`).
-- Policy overlay schema (30-001) — using deterministic synthetic mapping in harness; update when official schema lands.
-
-## Harness
-- Project: `src/Bench/StellaOps.Bench/PolicyCache/policy_cache_bench.py`.
-- Scenarios: cold cache, warm cache, mixed (70/30 warm/cold).
-- Metrics: throughput, p50/p95/p99 added latency per evaluation, RSS/managed MB, GC gen2, cache hit rate.
-- Inputs: policy baseline + reachability cache NDJSON.
-
-## Commands
-- 10k cache with baseline policies:
-  `python src/Bench/StellaOps.Bench/PolicyCache/policy_cache_bench.py --policies docs/samples/policy/policy-delta-baseline.ndjson --reachability-cache src/Bench/StellaOps.Bench/Signals/results/reachability-cache-10k.ndjson --output src/Bench/StellaOps.Bench/PolicyCache/results/policy-cache.ndjson --seed 20250101 --threads 1`
-- Swap cache path to `reachability-cache-50k.ndjson` to stress the larger dataset.
-
-## Acceptance
-- Cache input and policy baseline present with hashes. ✅
-- Cold/warm/mixed runs emit NDJSON with sorted keys; cache hit rate captured. ✅
-- Outputs hashed locally (`policy-cache.ndjson.sha256`) and ready for perf dashboard ingestion. ✅
-
-## Handoff
-Use cache outputs from BENCH-SIG-26-001 to run the above command. Compare added latency between cold vs warm runs; mixed scenario should stay within target thresholds (p95 delta ≤ configured budget).