feat(search): support platform and benchmark config filters

Add platform handling to submissions and persist a normalized value (`windows`, `linux`, `macos`) with a default of `windows` when omitted.

Extend search/index filtering to support `thread`, `platform`, `intensity`, and `durationSecs` alongside existing text/CPU token matching, and wire these params through request parsing, page data, and navigation URLs.

Update API/README docs and examples to reflect the new submission inputs and search capabilities so users can run more precise queries.feat(search): support platform and benchmark config filters

Add platform handling to submissions and persist a normalized value (`windows`, `linux`, `macos`) with a default of `windows` when omitted.

Extend search/index filtering to support `thread`, `platform`, `intensity`, and `durationSecs` alongside existing text/CPU token matching, and wire these params through request parsing, page data, and navigation URLs.

Update API/README docs and examples to reflect the new submission inputs and search capabilities so users can run more precise queries.

README.md

@@ -5,7 +5,7 @@ Production-oriented Go web application for ingesting CPU benchmark results, stor
 ## Features
 
 - `POST /api/submit` accepts either `application/json` or `multipart/form-data`.
-- `GET /api/search` performs case-insensitive token matching against submitter/general fields and CPU brand strings.
+- `GET /api/search` performs case-insensitive token matching against submitter/general fields and CPU brand strings, with explicit thread-mode, platform, intensity, and duration filters.
 - `GET /` renders the latest submissions with search and pagination.
 - BadgerDB stores each submission under a reverse-timestamp key so native iteration returns newest records first.
 - A startup-loaded in-memory search index prevents full DB deserialization for every query.
@@ -17,6 +17,7 @@ Each stored submission contains:
 
 - `submissionID`: server-generated UUID
 - `submitter`: defaults to `Anonymous` if omitted
+- `platform`: normalized to `windows`, `linux`, or `macos`; defaults to `windows` if omitted
 - `submittedAt`: server-side storage timestamp
 - Benchmark payload fields:
   - `config`
@@ -84,15 +85,21 @@ Accepted content types:
 
 JSON requests support either:
 
-1. A wrapper envelope with `submitter` and nested `benchmark`
+1. A wrapper envelope with `submitter`, `platform`, and nested `benchmark`
 2. A raw benchmark JSON body, with optional submitter provided via:
    - query string `?submitter=...`
    - header `X-Submitter`
    - top-level `submitter` field
+   - query string `?platform=...`
+   - header `X-Platform`
+   - top-level `platform` field
+
+`platform` is stored for every submission. Supported values are `windows`, `linux`, and `macos`. If the client does not send it, the server defaults to `windows`.
 
 Multipart requests support:
 
 - `submitter` text field
+- `platform` text field
 - benchmark JSON as one of these file fields: `benchmark`, `file`, `benchmarkFile`
 - or benchmark JSON as text fields: `benchmark`, `payload`, `result`, `data`
 
@@ -102,6 +109,7 @@ Example success response:
 {
   "success": true,
   "submissionID": "8f19d442-1be0-4989-97cf-3f8ee6b61548",
+  "platform": "windows",
   "submitter": "Workstation-Lab-A",
   "submittedAt": "2026-04-15T15:45:41.327225Z"
 }
@@ -113,11 +121,15 @@ Query parameters:
 
 - `text`: token-matches submitter and general searchable fields
 - `cpu`: token-matches `cpuInfo.brandString`
+- `thread`: `single` or `multi`
+- `platform`: `windows`, `linux`, or `macos`
+- `intensity`: exact match on `config.intensity`
+- `durationSecs`: exact match on `config.durationSecs`
 
 Example:
 
 ```bash
-curl "http://localhost:8080/api/search?text=intel&cpu=13700"
+curl "http://localhost:8080/api/search?text=intel&cpu=13700&thread=multi&platform=windows&intensity=10&durationSecs=30"
 ```
 
 ### `GET /`
@@ -127,13 +139,17 @@ Query parameters:
 - `page`
 - `text`
 - `cpu`
+- `thread`
+- `platform`
+- `intensity`
+- `durationSecs`
 
 Examples:
 
 ```text
 http://localhost:8080/
 http://localhost:8080/?page=2
-http://localhost:8080/?text=anonymous&cpu=ryzen
+http://localhost:8080/?text=anonymous&cpu=ryzen&thread=multi&platform=windows&intensity=10&durationSecs=20
 ```
 
 ## Request Examples
@@ -149,6 +165,7 @@ You can also submit one of the provided sample payloads directly:
 ```bash
 curl -X POST "http://localhost:8080/api/submit?submitter=Example-CLI" \
   -H "Content-Type: application/json" \
+  -H "X-Platform: windows" \
   --data-binary @example_jsons/5800X/cpu-bench-result.json
 ```
 
@@ -157,6 +174,7 @@ Or as multipart:
 ```bash
 curl -X POST "http://localhost:8080/api/submit" \
   -F "submitter=Example-Multipart" \
+  -F "platform=linux" \
   -F "benchmark=@example_jsons/i9/cpu-bench-result.json;type=application/json"
 ```
 
@@ -168,7 +186,7 @@ curl -X POST "http://localhost:8080/api/submit" \
   - canonical submission payload
   - normalized general search text
   - normalized CPU brand text
-- Searches scan the in-memory ordered slice rather than reopening and deserializing Badger values for every request.
+- Searches scan the in-memory ordered slice rather than reopening and deserializing Badger values for every request, and apply explicit platform, thread-mode, intensity, and duration filters in memory.
 
 ## Docker