Update README to reflect command-line flag configuration

- Replace environment variables with command-line flags
- Update run example with proper flag syntax
- Fix database schema path to misc/sql/initdb.sql
- Add missing configuration options (gopher, seed-url-path, max-db-connections)
- Remove outdated configuration options

NOTES.md

@@ -0,0 +1,13 @@
+# Notes
+
+Avoiding endless loops while crawling
+
+- Make sure we follow robots.txt
+- Announce our own agent so people can block us in their robots.txt
+- Put a limit on number of pages per host, and notify on limit reach.
+- Put a limit on the number of redirects (not needed?)
+
+Heuristics:
+
+- Do _not_ parse links from pages that have '/git/' or '/cgi/' or '/cgi-bin/' in their URLs.
+- Have a list of "whitelisted" hosts/urls that we visit in regular intervals.

README.md

@@ -22,12 +22,8 @@ This crawler uses `InsecureSkipVerify: true` in TLS configuration to accept all
 
 ## How to run
 
-```shell
-make build
-./dist/crawler --help
-```
-
-Check `misc/sql/initdb.sql` to create the PostgreSQL tables.
+Spin up a PostgreSQL, check `misc/sql/initdb.sql` to create the tables and start the crawler.
+All configuration is done via command-line flags.
 
 ## Configuration
 

TODO.md

@@ -0,0 +1,38 @@
+# TODO
+
+## Outstanding Issues
+
+### 1. Ctrl+C Signal Handling Issue
+
+**Problem**: The crawler sometimes doesn't exit properly when Ctrl+C is pressed.
+
+**Root Cause**: The main thread gets stuck in blocking operations before it can check for signals:
+- Database operations in the polling loop (`cmd/crawler/crawler.go:239-250`)
+- Job queueing when channel is full (`jobs <- url` can block if workers are slow)
+- Long-running database transactions
+
+**Location**: `cmd/crawler/crawler.go` - main polling loop starting at line 233
+
+**Solution**: Add signal/context checking to blocking operations:
+- Use cancellable context instead of `context.Background()` for database operations
+- Make job queueing non-blocking or context-aware
+- Add timeout/cancellation to database operations
+
+### 2. fetchSnapshotsFromHistory() Doesn't Work with --skip-identical-content=true
+
+**Problem**: When `--skip-identical-content=true` (default), URLs with unchanged content get continuously re-queued.
+
+**Root Cause**: The function tracks when content last changed, not when URLs were last crawled:
+- Identical content → no new snapshot created
+- Query finds old snapshot timestamp → re-queues URL
+- Creates infinite loop of re-crawling unchanged content
+
+**Location**: `cmd/crawler/crawler.go:388-470` - `fetchSnapshotsFromHistory()` function
+
+**Solution Options**:
+1. Add `last_crawled` timestamp to URLs table
+2. Create separate `crawl_attempts` table  
+3. Always create snapshot entries (even for duplicates) but mark them as such
+4. Modify logic to work with existing schema constraints
+
+**Current Status**: Function assumes `SkipIdenticalContent=false` per original comment at line 391.