docs: add CHANGELOG + finish reference glossary (v5.1)

- Add CHANGELOG.md (Keep-a-Changelog) seeded from RELEASE_NOTES.md, surfaced
  in the docs nav via docs/changelog.md (include-markdown). Closes #21.
- Glossary: add the remaining emitted-metric terms (EIRP, Sidelobe, Group
  delay, Cal drift). The glossary/measurement-types/mcp-overview pages were
  substantially rebuilt in v5.0.0; this finishes the metric coverage. Closes #20.
- mkdocs --strict builds clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: RFingAdam

CHANGELOG.md

@@ -0,0 +1,58 @@
+# Changelog
+
+All notable changes to RFlect are documented here. The format follows
+[Keep a Changelog](https://keepachangelog.com/en/1.1.0/) and the project adheres
+to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+Full, detailed per-release notes live in
+[RELEASE_NOTES.md](https://github.com/RFingAdam/RFlect/blob/main/RELEASE_NOTES.md); this file is the concise summary.
+
+## [Unreleased] — v5.1 (Correctness & quick wins)
+
+### Added
+- Golden-reference regression tests locking the TRP/gain integration core
+  (isotropic EIRP → itself; upper hemisphere → −3.01 dB).
+- `compute_group_delay_dispersion()` — per-frequency group-delay variance/std
+  across theta cuts (replaces the old dead TODO block).
+- Test coverage for previously-untested modules: `plotting.py`, `save.py`,
+  `groupdelay.py`, `plot_group_delay_cst.py`, `uwb_plotting.py`.
+
+### Changed
+- `cal_drift_report` MCP tool now returns `{output_path, format}` / `{error}`
+  and never raises to the client.
+- Slimmer install: `openai` moved to the `[ai]` extra; `keyring`/`cryptography`
+  dropped from core deps (unused since the v5.0.0 AI removal); `pyinstaller`
+  removed from the runtime requirements; numpy ceiling raised to `<3.0.0`.
+- GUI settings save/load and data-processing failures are now surfaced
+  (stderr / log) instead of being silently swallowed.
+
+### Docs
+- This changelog; expanded reference docs.
+
+## [5.0.0] — 2026-05-28
+
+**Zero-dependency, MCP-first relaunch.** Removed the entire in-app AI/LLM stack
+(chat, AI report generation, provider abstraction, API-key store) — RFlect makes
+no LLM/API calls and needs no key or subscription. `generate_report` is
+deterministic by default with an optional agent-authored `narrative`. Added 6
+MCP tools (compare_antennas, analyze_s11, analyze_group_delay,
+estimate_link_budget, analyze_mimo_diversity, generate_active_cal); MCP tool
+count 35 → 41. Renamed `ai_analysis.py` → `analysis_engine.py`.
+
+## [4.3.0] — 2026-05-28
+
+Multi-angle iperf throughput-validation MCP tool (`analyze_iperf_angle_sweep`).
+
+## [4.2.0] — 2026-05-12
+
+`process_folder` single-call folder-orchestration MCP tool; MkDocs Material docs
+site.
+
+## [4.1.9] — 2026-04-14
+
+Patch: restored the Active Chamber Calibration routine.
+
+---
+
+Earlier releases (4.1.8 and prior) are detailed in
+[RELEASE_NOTES.md](https://github.com/RFingAdam/RFlect/blob/main/RELEASE_NOTES.md).

docs/changelog.md

@@ -0,0 +1,3 @@
+{%
+  include-markdown "../CHANGELOG.md"
+%}

docs/reference/glossary.md

@@ -25,3 +25,7 @@
 | **VSWR** | Voltage Standing Wave Ratio. Derived from S11 magnitude. 1.0 = perfect match; 2.0 ≈ -9.5 dB return loss. |
 | **WTL** | Wireless Telecom Lab — the chamber-output format RFlect's parsers were built against (V5.02 / V5.03). |
 | **XPD** | Cross-Polarization Discrimination — co-pol field divided by cross-pol field, in dB. Uses 20 log, not 10 log. |
+| **EIRP** | Effective Isotropic Radiated Power — power radiated in a given direction relative to an isotropic source. RFlect's per-angle chamber input; TRP is its sphere average (the 1/4π in `calculate_trp`). |
+| **Sidelobe** | A radiation lobe other than the main beam; sidelobe level (SLL) is its peak relative to the main-lobe peak, in dB. |
+| **Group delay** | −dφ/dω, the negative derivative of transmission phase w.r.t. angular frequency (s); flatness across the band matters for wideband/UWB pulse fidelity. |
+| **Cal drift** | Change in a chamber's path-loss calibration factors over time; RFlect tracks runs across epochs and flags drift beyond a threshold. |

mkdocs.yml

@@ -110,4 +110,5 @@ nav:
       - CLI: reference/cli.md
       - API: reference/api.md
       - Glossary: reference/glossary.md
+  - Changelog: changelog.md
   - Contributing: contributing.md