feat(auth): JWT-or-static middleware + /.well-known/oauth-protected-resource (issue #5)

- internal/auth/jwt.go: JWTValidator via lestrrat-go/jwx/v2, JWKS auto-refresh
- internal/auth/bearer.go: replace Gitea PAT validation with JWT->static->default chain
- internal/gitea/client.go: always use service PAT; remove TokenFromContext lookup
- internal/config/config.go: add DexIssuerURL, MCPAudience, MCPResourceURL, StaticToken
- cmd/gitea-mcp/main.go: wire validator, fix /.well-known to return real AS list
- bearer_test.go: rewrite for new API

CLAUDE.md

@@ -0,0 +1,79 @@
+# Project context
+
+<!-- Canonical project context. Edit this, run `task context:sync`.
+     Root agent context from ~/dev/.context/AGENT.md is automatically
+     prepended for harnesses that don't walk the directory tree. -->
+
+## Identity
+
+- **Name**: gitea-mcp
+- **Owner**: Mathias
+- **Client**: personal
+- **Repo**: https://gitea.d-ma.be/mathias/gitea-mcp
+- **Status**: active
+
+## Stack
+
+- **Primary language**: Go
+- **UI layer**: HTMX + Templ (when applicable)
+- **Fallback languages**: Python, TypeScript (justify in PR if used)
+- **Build**: Task (taskfile.dev), not Make
+- **Containers**: Docker (compose for dev, k3s for deploy)
+- **Target infra**: koala (GPU workloads), iguana (services), flamingo (edge)
+
+## Conventions
+
+### Code style
+- Go: follow `golines`, `gofumpt`, `golangci-lint` with project config
+- Tests: table-driven, in `_test.go` next to source, `testify` for assertions
+- Errors: wrap with `fmt.Errorf("operation: %w", err)`, no naked returns
+- Naming: stdlib conventions, no stuttering (`http.Client` not `http.HTTPClient`)
+
+### Architecture preferences
+- Prefer standard library over frameworks (net/http over gin/echo)
+- Dependency injection via constructor functions, not containers
+- Configuration via environment variables, parsed at startup into a typed struct
+- Structured logging via `slog`
+
+### Git
+- Conventional commits: `feat:`, `fix:`, `chore:`, `docs:`, `refactor:`
+- Branch naming: `feat/short-description`, `fix/short-description`
+- PRs: one concern per PR, description explains *why* not *what*
+
+### Security
+- No secrets in code, ever — use env vars or SOPS-encrypted files
+- Client data never leaves local network unless explicitly cleared
+- Dependencies: audit with `govulncheck` before adding
+
+## Knowledge base access
+
+This project can query the shared knowledge base via MCP or HTTP:
+
+- **MCP endpoint**: `mcp://localhost:3100/knowledge`
+- **HTTP fallback**: `http://localhost:3100/api/v1/search`
+- **Scoping**: queries are filtered to collection `personal` + `public`
+
+## Behavior rules
+
+These rules apply to every task in this project, regardless of harness.
+
+1. **No assumptions.** Don't hide confusion — surface it. Surface tradeoffs explicitly.
+   Think before coding; if the problem is unclear, ask or state assumptions before acting.
+2. **Minimum viable code.** Solve with the smallest change that works. Nothing
+   speculative, no "while we're here" cleanups, no premature abstractions. Simplicity first.
+3. **Surgical changes.** Touch only what the task requires. Leave unrelated code,
+   files, and formatting alone. Diffs should be small and reviewable.
+4. **Goal-driven execution.** Define clear success criteria up front for every task.
+   Loop — implement, verify, refine — until those criteria are met. Don't claim
+   completion without evidence (tests pass, command output, observed behavior).
+
+## Agent instructions
+
+When acting as a coding agent on this project:
+
+1. Read this file and all `SKILL.md` files in `.skills/` before starting work
+2. Run `task check` before committing (lint + test + vet)
+3. If unsure about a convention, check `DECISIONS.md` or ask
+4. Never modify files outside the project root without explicit permission
+5. When adding a dependency, explain why in the commit message
+6. For client projects: never send code or context to cloud APIs — use local models via LiteLLM