add HTTP service hardening policy for 1.0 releases

Add comprehensive security hardening requirements to REPO_POLICIES.md
that HTTP/web services must satisfy before tagging 1.0. Covers security
headers (HSTS, CSP, XFO, X-Content-Type-Options, Referrer-Policy,
Permissions-Policy), request/response limits, slowloris timeouts, rate
limiting on password auth, CSRF, session cookie security, reverse proxy
IP detection, CORS restrictions, and error handling.

Also add corresponding checklist sections to EXISTING_REPO_CHECKLIST.md
and NEW_REPO_CHECKLIST.md for verification during repo setup.

prompts/EXISTING_REPO_CHECKLIST.md

@@ -1,6 +1,6 @@
 ---
 title: Existing Repo Checklist
-last_modified: 2026-02-22
+last_modified: 2026-03-10
 ---
 
 Use this checklist when beginning work in a repo that may not yet conform to our
@@ -78,6 +78,22 @@ with your task.
       `internal/`, `static/`, etc.)
 - [ ] Go migrations in `internal/db/migrations/` and embedded in binary
 
+# HTTP Service Hardening (if targeting 1.0 and the repo is an HTTP/web service)
+
+- [ ] Security headers set on all responses (HSTS, CSP, X-Frame-Options,
+      X-Content-Type-Options, Referrer-Policy, Permissions-Policy)
+- [ ] Request body size limits enforced on all endpoints
+- [ ] Read/write/idle timeouts configured on the HTTP server (slowloris defense)
+- [ ] Per-handler execution time limits in place
+- [ ] Password-based auth endpoints are rate-limited
+- [ ] CSRF tokens on all state-mutating HTML forms
+- [ ] Passwords hashed with bcrypt, scrypt, or argon2
+- [ ] Session cookies use HttpOnly, Secure, and SameSite attributes
+- [ ] True client IP correctly detected behind reverse proxy (trusted proxy
+      allowlist configured)
+- [ ] CORS restricted to explicit origin allowlist for authenticated endpoints
+- [ ] Error responses do not leak stack traces, SQL queries, or internal paths
+
 # Final
 
 - [ ] `make check` passes

prompts/NEW_REPO_CHECKLIST.md

@@ -1,6 +1,6 @@
 ---
 title: New Repo Checklist
-last_modified: 2026-02-22
+last_modified: 2026-03-10
 ---
 
 Use this checklist when creating a new repository from scratch. Follow the steps
@@ -84,7 +84,22 @@ Template files can be fetched from:
 - [ ] No unnecessary files in repo root
 - [ ] All dates written as YYYY-MM-DD
 
-# 5. Merge and Set Up
+# 5. HTTP Service Hardening (if the repo is an HTTP/web service targeting 1.0)
+
+- [ ] Security headers middleware configured (HSTS, CSP, X-Frame-Options,
+      X-Content-Type-Options, Referrer-Policy, Permissions-Policy)
+- [ ] Request body size limits enforced on all endpoints
+- [ ] HTTP server read/write/idle timeouts configured (slowloris defense)
+- [ ] Per-handler execution time limits in place
+- [ ] Rate limiting on password-based authentication endpoints
+- [ ] CSRF tokens on all state-mutating HTML forms
+- [ ] Password hashing uses bcrypt, scrypt, or argon2
+- [ ] Session cookies set with HttpOnly, Secure, and SameSite attributes
+- [ ] True client IP detection configured with trusted proxy allowlist
+- [ ] CORS restricted to explicit origin allowlist for authenticated endpoints
+- [ ] Error responses never leak stack traces, SQL queries, or internal paths
+
+# 6. Merge and Set Up
 
 - [ ] Commit, merge to `main`
 - [ ] `make hooks` to install pre-commit hook

prompts/REPO_POLICIES.md

@@ -1,6 +1,6 @@
 ---
 title: Repository Policies
-last_modified: 2026-03-09
+last_modified: 2026-03-10
 ---
 
 This document covers repository structure, tooling, and workflow standards. Code
@@ -128,6 +128,65 @@ style conventions are in separate documents:
 - Dockerized web services listen on port 8080 by default, overridable with
   `PORT`.
 
+- **HTTP/web services must be hardened for production internet exposure before
+  tagging 1.0.** This means full compliance with security best practices
+  including, without limitation, all of the following:
+    - **Security headers** on every response:
+        - `Strict-Transport-Security` (HSTS) with `max-age` of at least one year
+          and `includeSubDomains`.
+        - `Content-Security-Policy` (CSP) with a restrictive default policy
+          (`default-src 'self'` as a baseline, tightened per-resource as
+          needed). Never use `unsafe-inline` or `unsafe-eval` unless
+          unavoidable, and document the reason.
+        - `X-Frame-Options: DENY` (or `SAMEORIGIN` if framing is required).
+          Prefer the `frame-ancestors` CSP directive as the primary control.
+        - `X-Content-Type-Options: nosniff`.
+        - `Referrer-Policy: strict-origin-when-cross-origin` (or stricter).
+        - `Permissions-Policy` restricting access to browser features the
+          application does not use (camera, microphone, geolocation, etc.).
+    - **Request and response limits:**
+        - Maximum request body size enforced on all endpoints (e.g. Go
+          `http.MaxBytesReader`). Choose a sane default per-route; never accept
+          unbounded input.
+        - Maximum response body size where applicable (e.g. paginated APIs).
+        - `ReadTimeout` and `ReadHeaderTimeout` on the `http.Server` to defend
+          against slowloris attacks.
+        - `WriteTimeout` on the `http.Server`.
+        - `IdleTimeout` on the `http.Server`.
+        - Per-handler execution time limits via `context.WithTimeout` or
+          chi/stdlib `middleware.Timeout`.
+    - **Authentication and session security:**
+        - Rate limiting on password-based authentication endpoints. API keys are
+          high-entropy and not susceptible to brute force, so they are exempt.
+        - CSRF tokens on all state-mutating HTML forms. API endpoints
+          authenticated via `Authorization` header (Bearer token, API key) are
+          exempt because the browser does not attach these automatically.
+        - Passwords stored using bcrypt, scrypt, or argon2 — never plain-text,
+          MD5, or SHA.
+        - Session cookies set with `HttpOnly`, `Secure`, and `SameSite=Lax` (or
+          `Strict`) attributes.
+    - **Reverse proxy awareness:**
+        - True client IP detection when behind a reverse proxy
+          (`X-Forwarded-For`, `X-Real-IP`). The application must accept
+          forwarded headers only from a configured set of trusted proxy
+          addresses — never trust `X-Forwarded-For` unconditionally.
+    - **CORS:**
+        - Authenticated endpoints must restrict `Access-Control-Allow-Origin` to
+          an explicit allowlist of known origins. Wildcard (`*`) is acceptable
+          only for public, unauthenticated read-only APIs.
+    - **Error handling:**
+        - Internal errors must never leak stack traces, SQL queries, file paths,
+          or other implementation details to the client. Return generic error
+          messages in production; detailed errors only when `DEBUG` is enabled.
+    - **TLS:**
+        - The service itself may terminate TLS or sit behind a TLS-terminating
+          reverse proxy, but HSTS headers and secure cookie flags must be set
+          regardless so that the browser enforces HTTPS.
+
+    This list is non-exhaustive. Apply defense-in-depth: if a standard security
+    hardening measure exists for HTTP services and is not listed here, it is
+    still expected. When in doubt, harden.
+
 - `README.md` is the primary documentation. Required sections:
     - **Description**: First line must include the project name, purpose,
       category (web server, SPA, CLI tool, etc.), license, and author. Example: